/* ============================================================
   SUITS DSA TRACKER — THE EXECUTIVE OBSIDIAN DESIGN SYSTEM
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Manrope:wght@300;400;600;700;800;900&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@20..48,100..700,0..1,-50..200&display=swap');

/* ─── DESIGN TOKENS ─── */
:root {
  /* Core Surface Architecture */
  --surface:               #131313;
  --surface-dim:           #131313;
  --surface-bright:        #393939;
  --surface-container-lowest: #0e0e0e;
  --surface-container-low: #1c1b1b;
  --surface-container:     #201f1f;
  --surface-container-high:#2a2a2a;
  --surface-container-highest: #353534;
  --surface-variant:       #353534;

  /* Brand Palette */
  --primary:               #ffc78b;
  --primary-container:     #ffa116;
  --primary-fixed:         #ffddba;
  --primary-fixed-dim:     #ffb867;
  --on-primary:            #482900;
  --on-primary-fixed:      #2b1700;
  --on-primary-container:  #683e00;

  --secondary:             #f2bc82;
  --secondary-container:   #664112;
  --secondary-fixed:       #ffddba;
  --secondary-fixed-dim:   #f2bc82;
  --on-secondary:          #482900;
  --on-secondary-container:#e3af75;

  --tertiary:              #94dbff;
  --tertiary-container:    #02c4ff;
  --on-tertiary:           #003547;
  --on-tertiary-container: #004d67;

  /* Text & Outline */
  --on-surface:            #e5e2e1;
  --on-surface-variant:    #d9c3ad;
  --outline:               #a18d7a;
  --outline-variant:       #544434;
  --inverse-surface:       #e5e2e1;
  --inverse-on-surface:    #313030;

  /* Error */
  --error:                 #ffb4ab;
  --error-container:       #93000a;
  --on-error:              #690005;
  --on-error-container:    #ffdad6;

  /* Utility */
  --surface-tint:          #ffb867;
  --background:            #131313;
  --on-background:         #e5e2e1;

  /* Spacing */
  --sidebar-w: 16rem;
  --topbar-h: 5rem;

  /* Radius */
  --radius-sm:   0.375rem;
  --radius-md:   0.75rem;
  --radius-lg:   1rem;
  --radius-xl:   1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur-fast: 150ms;
  --dur-med:  250ms;
  --dur-slow: 400ms;
}

/* ─── RESET & BASE ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--surface);
  color: var(--on-surface);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  /* Subtle ambient glow */
  background-image:
    radial-gradient(ellipse at 0% 0%, rgba(255,161,22,0.04) 0%, transparent 50%),
    radial-gradient(ellipse at 100% 100%, rgba(148,219,255,0.025) 0%, transparent 50%);
}

h1, h2, h3, h4, h5, h6 { font-family: 'Manrope', sans-serif; }

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
input, textarea, select { font-family: inherit; }

::selection {
  background-color: rgba(255,161,22,0.3);
  color: var(--on-primary-fixed);
}

/* ─── SCROLLBAR ─── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--surface-container-lowest); }
::-webkit-scrollbar-thumb { background: var(--outline-variant); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--outline); }

/* ─── MATERIAL ICONS ─── */
.material-symbols-outlined {
  font-family: 'Material Symbols Outlined';
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  user-select: none;
  line-height: 1;
  font-size: 1.5rem;
  vertical-align: middle;
}
.icon-fill { font-variation-settings: 'FILL' 1, 'wght' 400, 'GRAD' 0, 'opsz' 24; }

/* ═══════════════════════════════════════════════════
   LAYOUT SHELL
═══════════════════════════════════════════════════ */

/* ─── TOPBAR ─── */
.topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--topbar-h);
  z-index: 100;
  background: rgba(32, 31, 31, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(84,68,52,0.12);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  box-shadow: 0 20px 40px rgba(0,0,0,0.35);
}

.topbar-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.topbar-logo {
  font-family: 'Manrope', sans-serif;
  font-size: 1.375rem;
  font-weight: 900;
  letter-spacing: -0.05em;
  color: var(--primary-container);
}
.topbar-tagline {
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  display: none;
}

.topbar-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}
.topbar-nav a {
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--on-surface-variant);
  transition: all var(--dur-fast) var(--ease);
}
.topbar-nav a:hover { color: var(--on-surface); background: rgba(255,255,255,0.05); }
.topbar-nav a.active { color: var(--primary-container); font-weight: 600; }

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.topbar-icon-btn {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--radius-full);
  display: flex; align-items: center; justify-content: center;
  color: var(--on-surface-variant);
  transition: all var(--dur-fast) var(--ease);
}
.topbar-icon-btn:hover { background: var(--surface-bright); color: var(--on-surface); }
.topbar-avatar {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--radius-full);
  background: var(--secondary-container);
  border: 1.5px solid rgba(84,68,52,0.35);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--on-secondary-container);
  cursor: pointer;
  overflow: hidden;
  transition: border-color var(--dur-fast) var(--ease);
}
.topbar-avatar:hover { border-color: var(--primary-container); }
.topbar-avatar img { width: 100%; height: 100%; object-fit: cover; }

/* Mobile menu toggle */
.hamburger-btn {
  display: flex; align-items: center; justify-content: center;
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--radius-md);
  color: var(--on-surface-variant);
  transition: all var(--dur-fast) var(--ease);
}
.hamburger-btn:hover { background: var(--surface-container-high); }

/* ─── SIDEBAR ─── */
.sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: var(--sidebar-w);
  z-index: 90;
  background: rgba(28, 27, 27, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-right: 1px solid rgba(84,68,52,0.1);
  display: flex;
  flex-direction: column;
  padding: calc(var(--topbar-h) + 1.5rem) 0.75rem 1.5rem;
  transition: transform var(--dur-slow) var(--ease);
}

.sidebar-logo-area {
  padding: 0 0.75rem 2rem;
}
.sidebar-brand {
  font-family: 'Manrope', sans-serif;
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  color: var(--primary-container);
}
.sidebar-sub {
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  margin-top: 2px;
}

.sidebar-nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
  list-style: none;
}

.sidebar-nav-item a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--on-surface-variant);
  transition: all var(--dur-fast) var(--ease);
  position: relative;
}
.sidebar-nav-item a:hover {
  background: var(--surface-container-high);
  color: var(--on-surface);
}
.sidebar-nav-item a.active {
  color: var(--primary-container);
  background: linear-gradient(90deg, rgba(255,161,22,0.12) 0%, transparent 100%);
  font-weight: 600;
}
.sidebar-nav-item a.active::before {
  content: '';
  position: absolute;
  left: 0; top: 20%; bottom: 20%;
  width: 2px;
  border-radius: 1px;
  background: var(--primary-container);
}

.sidebar-section-label {
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--outline);
  padding: 1.25rem 1rem 0.5rem;
}

.sidebar-bottom {
  display: flex;
  flex-direction: column;
  gap: 2px;
  border-top: 1px solid rgba(84,68,52,0.1);
  padding-top: 0.75rem;
  margin-top: 0.75rem;
}

/* ─── SIDEBAR OVERLAY (mobile) ─── */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 89;
  backdrop-filter: blur(4px);
}
.sidebar-overlay.visible { display: block; }

/* ─── MAIN CONTENT ─── */
.main-content {
  margin-left: var(--sidebar-w);
  padding-top: calc(var(--topbar-h) + 2rem);
  padding-bottom: 4rem;
  padding-left: 2.5rem;
  padding-right: 2.5rem;
  min-height: 100vh;
  max-width: calc(var(--sidebar-w) + 90rem);
}

/* ═══════════════════════════════════════════════════
   UTILITY CLASSES
═══════════════════════════════════════════════════ */
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; clip: rect(0,0,0,0); }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }
.w-full { width: 100%; }
.text-center { text-align: center; }
.mt-auto { margin-top: auto; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }
.mb-12 { margin-bottom: 3rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.p-2 { padding: 0.5rem; }
.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }
.p-8 { padding: 2rem; }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.relative { position: relative; }
.overflow-hidden { overflow: hidden; }
.cursor-pointer { cursor: pointer; }

/* Typography helpers */
.text-xs  { font-size: 0.75rem; line-height: 1rem; }
.text-sm  { font-size: 0.875rem; line-height: 1.25rem; }
.text-base{ font-size: 1rem; line-height: 1.5rem; }
.text-lg  { font-size: 1.125rem; line-height: 1.75rem; }
.text-xl  { font-size: 1.25rem; line-height: 1.75rem; }
.text-2xl { font-size: 1.5rem; line-height: 2rem; }
.text-3xl { font-size: 1.875rem; line-height: 2.25rem; }
.text-4xl { font-size: 2.25rem; line-height: 2.5rem; }
.text-5xl { font-size: 3rem; line-height: 1; }
.font-light   { font-weight: 300; }
.font-normal  { font-weight: 400; }
.font-medium  { font-weight: 500; }
.font-semibold{ font-weight: 600; }
.font-bold    { font-weight: 700; }
.font-extrabold{ font-weight: 800; }
.font-black   { font-weight: 900; }
.font-headline{ font-family: 'Manrope', sans-serif; }
.tracking-tight   { letter-spacing: -0.025em; }
.tracking-tighter { letter-spacing: -0.05em; }
.tracking-wide    { letter-spacing: 0.025em; }
.tracking-widest  { letter-spacing: 0.1em; }
.uppercase { text-transform: uppercase; }
.leading-none   { line-height: 1; }
.leading-tight  { line-height: 1.25; }
.leading-relaxed{ line-height: 1.625; }

/* Color helpers */
.text-primary         { color: var(--primary); }
.text-primary-container{ color: var(--primary-container); }
.text-secondary       { color: var(--secondary); }
.text-tertiary        { color: var(--tertiary); }
.text-on-surface      { color: var(--on-surface); }
.text-on-surface-variant { color: var(--on-surface-variant); }
.text-on-secondary-container { color: var(--on-secondary-container); }
.text-error           { color: var(--error); }
.text-on-error-container { color: var(--on-error-container); }
.bg-surface           { background: var(--surface); }
.bg-surface-container { background: var(--surface-container); }
.bg-surface-container-high { background: var(--surface-container-high); }
.bg-surface-container-low { background: var(--surface-container-low); }
.bg-primary-container { background: var(--primary-container); }
.rounded-full { border-radius: var(--radius-full); }
.rounded-xl   { border-radius: var(--radius-xl); }
.rounded-lg   { border-radius: var(--radius-lg); }
.rounded-md   { border-radius: var(--radius-md); }

/* ═══════════════════════════════════════════════════
   COMPONENTS
═══════════════════════════════════════════════════ */

/* ─── CARDS ─── */
.card {
  background: var(--surface-container);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(84,68,52,0.08);
  padding: 1.75rem;
  transition: background var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}
.card:hover { background: var(--surface-container-high); }
.card-low {
  background: var(--surface-container-low);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(84,68,52,0.06);
  padding: 1.75rem;
}
.card-glass {
  background: rgba(32,31,31,0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(84,68,52,0.15);
  padding: 1.75rem;
}

/* ─── BUTTONS ─── */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: 'Manrope', sans-serif;
  transition: all var(--dur-med) var(--ease);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-container) 100%);
  color: var(--on-primary-fixed);
  box-shadow: 0 0 15px rgba(255,161,22,0.25);
}
.btn-primary:hover {
  box-shadow: 0 0 30px rgba(255,161,22,0.45);
  transform: translateY(-1px);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 1px solid rgba(84,68,52,0.4);
}
.btn-secondary:hover {
  background: rgba(255,161,22,0.08);
  border-color: rgba(255,161,22,0.3);
}

.btn-ghost {
  background: transparent;
  color: var(--on-surface-variant);
  border: 1px solid rgba(84,68,52,0.25);
}
.btn-ghost:hover { background: var(--surface-container-high); color: var(--on-surface); }

.btn-sm { padding: 0.5rem 1rem; font-size: 0.8125rem; border-radius: var(--radius-md); }
.btn-lg { padding: 1rem 2rem; font-size: 1rem; border-radius: var(--radius-xl); }
.btn-icon {
  padding: 0.6rem;
  border-radius: var(--radius-md);
}
.btn-icon-round {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--radius-full);
  padding: 0;
}

/* ─── BADGES / CHIPS ─── */
.chip {
  display: inline-flex; align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.625rem;
  border-radius: var(--radius-full);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  font-family: 'Inter', sans-serif;
  white-space: nowrap;
}
.chip-easy   { background: rgba(102,65,18,0.4); color: #a8e6cf; }
.chip-medium { background: rgba(255,161,22,0.12); color: var(--primary-container); }
.chip-hard   { background: rgba(147,0,10,0.3); color: var(--on-error-container); }
.chip-topic  { background: rgba(84,68,52,0.25); color: var(--on-surface-variant); }
.chip-solved { background: rgba(102,65,18,0.5); color: var(--on-secondary-container); }
.chip-ai     { background: rgba(2,196,255,0.1); color: var(--tertiary); }

/* ─── PROGRESS BARS ─── */
.progress-track {
  width: 100%;
  height: 6px;
  background: var(--surface-container-lowest);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-container) 100%);
  transition: width 0.8s var(--ease);
  box-shadow: 0 0 8px rgba(255,161,22,0.4);
}
.progress-fill-tertiary {
  background: linear-gradient(90deg, rgba(148,219,255,0.5) 0%, var(--tertiary) 100%);
  box-shadow: 0 0 8px rgba(148,219,255,0.3);
}
.progress-track-thin { height: 3px; }

/* ─── INPUTS ─── */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.input-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--on-surface-variant);
  letter-spacing: 0.02em;
}
.input-field {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--surface-container-lowest);
  border: 1.5px solid rgba(84,68,52,0.3);
  border-radius: var(--radius-md);
  color: var(--on-surface);
  font-size: 0.875rem;
  font-family: 'Inter', sans-serif;
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
  outline: none;
}
.input-field::placeholder { color: var(--outline); }
.input-field:focus {
  border-color: var(--primary-container);
  box-shadow: 0 0 0 3px rgba(255,161,22,0.12);
}
.input-field:hover:not(:focus) { border-color: var(--outline); }

.input-with-icon {
  position: relative;
}
.input-with-icon .input-field {
  padding-left: 2.75rem;
}
.input-with-icon .input-icon {
  position: absolute;
  left: 0.875rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--outline);
  font-size: 1.125rem;
  pointer-events: none;
}

/* ─── SELECT ─── */
.select-field {
  width: 100%;
  padding: 0.6875rem 2.5rem 0.6875rem 1rem;
  background: var(--surface-container-lowest);
  border: 1.5px solid rgba(84,68,52,0.3);
  border-radius: var(--radius-md);
  color: var(--on-surface);
  font-size: 0.875rem;
  font-family: 'Inter', sans-serif;
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%23a18d7a' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1.25em;
  cursor: pointer;
  outline: none;
  transition: border-color var(--dur-fast) var(--ease);
}
.select-field:focus { border-color: var(--primary-container); }
.select-field option { background: var(--surface-container-high); }

/* ─── CHECKBOX ─── */
.checkbox-wrapper {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  cursor: pointer;
}
.checkbox-input {
  appearance: none;
  -webkit-appearance: none;
  width: 1.125rem; height: 1.125rem;
  border: 1.5px solid rgba(84,68,52,0.5);
  border-radius: 4px;
  background: var(--surface-container-lowest);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
  flex-shrink: 0;
  position: relative;
}
.checkbox-input:checked {
  background: var(--primary-container);
  border-color: var(--primary-container);
}
.checkbox-input:checked::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 16 16' fill='%232b1700' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M12.207 4.793a1 1 0 010 1.414l-5 5a1 1 0 01-1.414 0l-2-2a1 1 0 011.414-1.414L6.5 9.086l4.293-4.293a1 1 0 011.414 0z'/%3e%3c/svg%3e");
  background-size: 100%;
}
.checkbox-input:hover { border-color: var(--primary-container); }
.checkbox-label { font-size: 0.875rem; color: var(--on-surface); }
.problem-row.solved .checkbox-label { color: var(--on-surface-variant); }
.problem-row.solved .problem-title { text-decoration: line-through; opacity: 0.6; }

/* ─── TABS ─── */
.tabs {
  display: flex;
  gap: 0.25rem;
  background: var(--surface-container-lowest);
  padding: 0.25rem;
  border-radius: var(--radius-lg);
  width: fit-content;
}
.tab-item {
  padding: 0.5rem 1.125rem;
  border-radius: var(--radius-md);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--on-surface-variant);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
  white-space: nowrap;
  border: none;
  background: none;
}
.tab-item:hover { color: var(--on-surface); }
.tab-item.active {
  background: var(--surface-container-high);
  color: var(--primary-container);
  box-shadow: 0 1px 4px rgba(0,0,0,0.25);
}

/* ─── SEARCH BAR ─── */
.search-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--surface-container-lowest);
  border: 1.5px solid rgba(84,68,52,0.2);
  border-radius: var(--radius-lg);
  padding: 0.625rem 1rem;
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}
.search-bar:focus-within {
  border-color: rgba(255,161,22,0.35);
  box-shadow: 0 0 0 3px rgba(255,161,22,0.08);
}
.search-bar input {
  background: none; border: none; outline: none;
  color: var(--on-surface); font-size: 0.875rem;
  flex: 1; min-width: 0;
}
.search-bar input::placeholder { color: var(--outline); }
.search-bar .material-symbols-outlined { color: var(--outline); font-size: 1.125rem; flex-shrink: 0; }

/* ─── STAT CARDS ─── */
.stat-card {
  background: var(--surface-container);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(84,68,52,0.08);
  padding: 1.75rem;
  transition: all var(--dur-med) var(--ease);
  position: relative;
  overflow: hidden;
}
.stat-card::after {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 120px; height: 120px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255,161,22,0.04) 0%, transparent 70%);
  transform: translate(30px, -30px);
  pointer-events: none;
}
.stat-card:hover { background: var(--surface-container-high); }
.stat-label {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  margin-bottom: 1rem;
}
.stat-value {
  font-family: 'Manrope', sans-serif;
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1;
  color: var(--on-surface);
  letter-spacing: -0.04em;
}
.stat-value-md {
  font-family: 'Manrope', sans-serif;
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1;
  color: var(--on-surface);
  letter-spacing: -0.04em;
}
.stat-subtext {
  font-size: 0.8125rem;
  color: var(--on-surface-variant);
  margin-top: 0.375rem;
}
.stat-accent { color: var(--primary); }

/* ─── PROBLEM ROWS ─── */
.problems-table {
  width: 100%;
  border-collapse: collapse;
}
.problems-table thead th {
  padding: 0.75rem 1rem;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--on-surface-variant);
  text-align: left;
  border-bottom: 1px solid rgba(84,68,52,0.1);
}
.problem-row {
  border-radius: var(--radius-md);
  transition: background var(--dur-fast) var(--ease);
}
.problem-row td {
  padding: 0.875rem 1rem;
  vertical-align: middle;
}
.problem-row:hover td { background: rgba(255,255,255,0.025); }
.problem-row:hover td:first-child { border-radius: var(--radius-md) 0 0 var(--radius-md); }
.problem-row:hover td:last-child { border-radius: 0 var(--radius-md) var(--radius-md) 0; }
.problem-title {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--on-surface);
  transition: color var(--dur-fast) var(--ease);
}
.problem-title a:hover { color: var(--primary); }
.problem-number {
  font-size: 0.8125rem;
  color: var(--outline);
  font-variant-numeric: tabular-nums;
  min-width: 2.5rem;
}

/* ─── PROBLEMS: VIEW SWITCH ─── */
.problems-view-switch {
  display: inline-flex;
  gap: 0.5rem;
  background: rgba(255,255,255,0.02);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 999px;
  padding: 0.25rem;
}
.problems-view-switch .btn.active {
  background: rgba(255,161,22,0.16);
  border-color: rgba(255,161,22,0.28);
  color: var(--primary-container);
}

/* ─── PROBLEMS: TREE ROADMAP ─── */
.roadmap-tree-wrap {
  padding: 1rem 1.1rem 1.25rem;
  background: radial-gradient(circle at 80% 20%, rgba(255,161,22,0.08), transparent 45%);
}
.roadmap-tree-canvas {
  display: grid;
  gap: 1.35rem;
}
.roadmap-topic {
  position: relative;
  display: grid;
  grid-template-columns: minmax(210px, 280px) 1fr;
  gap: 1rem;
  align-items: start;
}
.roadmap-topic:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 138px;
  top: calc(100% - 0.15rem);
  width: 2px;
  height: 1.45rem;
  background: linear-gradient(to bottom, rgba(255,161,22,0.45), rgba(255,161,22,0.05));
}
.roadmap-topic-card {
  border: 1px solid rgba(255,161,22,0.28);
  border-radius: 14px;
  background: linear-gradient(145deg, rgba(255,161,22,0.18), rgba(15,15,17,0.9));
  box-shadow: 0 14px 30px rgba(0,0,0,0.32);
  padding: 0.75rem 0.85rem 0.72rem;
}
.roadmap-topic.is-complete .roadmap-topic-card {
  border-color: rgba(168,230,207,0.5);
  background: linear-gradient(145deg, rgba(168,230,207,0.18), rgba(15,15,17,0.9));
}
.roadmap-node-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.65rem;
  align-items: center;
}
.roadmap-node-order {
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(255,161,22,0.2);
  color: var(--primary-container);
  font-size: 0.8rem;
  font-weight: 800;
}
.roadmap-node-meta h3 {
  margin: 0;
  font-size: 0.92rem;
  color: var(--on-surface);
  font-weight: 800;
}
.roadmap-node-meta p {
  margin: 0.15rem 0 0;
  font-size: 0.74rem;
  color: var(--on-surface-variant);
}
.roadmap-progress {
  margin-top: 0.65rem;
  height: 6px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  overflow: hidden;
}
.roadmap-progress > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #ffa116, #94dbff);
}
.roadmap-branches {
  position: relative;
  margin-left: 0.25rem;
  padding-left: 1rem;
  display: grid;
  gap: 0.58rem;
}
.roadmap-branches::before {
  content: '';
  position: absolute;
  left: 0.1rem;
  top: 0.35rem;
  bottom: 0.35rem;
  width: 2px;
  background: linear-gradient(to bottom, rgba(255,161,22,0.55), rgba(255,161,22,0.12));
}
.roadmap-branch-row {
  position: relative;
}
.roadmap-branch-row::before {
  content: '';
  position: absolute;
  left: -0.9rem;
  top: 1.05rem;
  width: 0.95rem;
  height: 2px;
  background: rgba(255,161,22,0.5);
}
.roadmap-question-card {
  background: rgba(17,17,19,0.88);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 12px;
  padding: 0.5rem 0.6rem;
}
.roadmap-branch-row.is-solved .roadmap-question-card {
  border-color: rgba(168,230,207,0.45);
  background: rgba(168,230,207,0.08);
}
.roadmap-leaf-head {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.55rem;
}
.roadmap-leaf-content p {
  margin: 0;
  font-size: 0.8rem;
  color: var(--on-surface);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.roadmap-leaf-content small {
  display: block;
  margin-top: 0.1rem;
  font-size: 0.68rem;
  color: var(--on-surface-variant);
}
.roadmap-question-actions {
  margin-top: 0.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.roadmap-action-btn {
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.03);
  color: var(--on-surface-variant);
  border-radius: 8px;
  padding: 0.25rem 0.45rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.68rem;
  cursor: pointer;
  transition: all 140ms ease;
}
.roadmap-action-btn .material-symbols-outlined {
  font-size: 0.9rem;
}
.roadmap-action-btn:hover {
  background: rgba(255,161,22,0.14);
  border-color: rgba(255,161,22,0.35);
  color: var(--primary-container);
}

@media (max-width: 900px) {
  .roadmap-topic {
    grid-template-columns: 1fr;
    gap: 0.65rem;
  }
  .roadmap-topic::after { display: none; }
  .roadmap-branches { margin-left: 0; }
}

/* ─── TOAST NOTIFICATIONS ─── */
.toast-container {
  position: fixed;
  bottom: 1.5rem; right: 1.5rem;
  z-index: 9999;
  display: flex; flex-direction: column; gap: 0.5rem;
}
.toast {
  background: var(--surface-container-highest);
  border: 1px solid rgba(84,68,52,0.2);
  border-radius: var(--radius-xl);
  padding: 0.875rem 1.25rem;
  display: flex; align-items: center; gap: 0.75rem;
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
  font-size: 0.875rem;
  backdrop-filter: blur(12px);
  animation: toast-in var(--dur-med) var(--ease);
  max-width: 20rem;
}
.toast-success .toast-icon { color: var(--secondary); }
.toast-error .toast-icon { color: var(--error); }
.toast-info .toast-icon { color: var(--tertiary); }
@keyframes toast-in {
  from { opacity: 0; transform: translateY(1rem) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toast-out {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(1rem) scale(0.95); }
}

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 10000;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-lg);
  background: var(--surface-container-highest);
  color: var(--on-surface);
  border: 1px solid rgba(255,161,22,0.25);
  transform: translateY(-140%);
  transition: transform var(--dur-fast) var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

.page-status-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin: 0 0 1rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(211, 47, 47, 0.28);
  background: rgba(211, 47, 47, 0.09);
  color: #ffb7b7;
  box-shadow: 0 20px 30px rgba(0,0,0,0.18);
}

.page-status-copy {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 0;
}

.page-status-copy p {
  margin: 0;
  font-size: 0.9rem;
}

.page-status-copy .material-symbols-outlined {
  color: #ff8888;
}

.page-status-banner .btn {
  flex: 0 0 auto;
  border-color: rgba(211, 47, 47, 0.24);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--primary-container);
  outline-offset: 3px;
  box-shadow: 0 0 0 4px rgba(255,161,22,0.12);
}

@media (max-width: 768px) {
  .page-status-banner {
    flex-direction: column;
    align-items: stretch;
  }
}

/* ─── SECTION HEADERS ─── */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.section-title {
  font-family: 'Manrope', sans-serif;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--on-surface);
  letter-spacing: -0.02em;
}
.section-count {
  font-size: 0.8125rem;
  color: var(--on-surface-variant);
  font-weight: 500;
}

/* ─── MODAL ─── */
.modal-backdrop {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(8px);
  z-index: 200;
  display: flex; align-items: center; justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-med) var(--ease);
}
.modal-backdrop.visible {
  opacity: 1;
  pointer-events: all;
}
.modal {
  background: var(--surface-container-highest);
  border: 1px solid rgba(84,68,52,0.2);
  border-radius: var(--radius-xl);
  padding: 2rem;
  width: 100%; max-width: 32rem;
  box-shadow: 0 40px 80px rgba(0,0,0,0.5);
  transform: scale(0.95) translateY(1rem);
  transition: transform var(--dur-med) var(--ease);
}
.modal-backdrop.visible .modal {
  transform: scale(1) translateY(0);
}
.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 1.5rem;
}
.modal-title { font-size: 1.125rem; font-weight: 700; font-family: 'Manrope', sans-serif; }
.modal-close {
  width: 2rem; height: 2rem;
  border-radius: var(--radius-full);
  display: flex; align-items: center; justify-content: center;
  color: var(--on-surface-variant);
  transition: all var(--dur-fast) var(--ease);
}
.modal-close:hover { background: var(--surface-bright); color: var(--on-surface); }

/* ─── DONUT CHART ─── */
.donut-chart { position: relative; }
.donut-center {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  pointer-events: none;
}

/* ─── AI INSIGHT BOX ─── */
.ai-insight {
  background: linear-gradient(135deg, rgba(255,161,22,0.06) 0%, rgba(148,219,255,0.04) 100%);
  border: 1px solid rgba(255,161,22,0.15);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}
.ai-insight::before {
  content: '';
  position: absolute;
  top: -1px; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--primary-container) 0%, var(--tertiary) 100%);
}
.ai-insight-header {
  display: flex; align-items: center; gap: 0.5rem;
  margin-bottom: 0.75rem;
}
.ai-insight-icon { color: var(--primary-container); font-size: 1.125rem; }
.ai-insight-label {
  font-size: 0.6875rem; font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--primary-container);
}
.ai-insight-text {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--on-surface-variant);
}
.ai-insight-loading {
  display: flex; gap: 4px; align-items: center;
}
.ai-dot {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--primary-container);
  animation: ai-pulse 1.2s ease infinite;
}
.ai-dot:nth-child(2) { animation-delay: 0.2s; }
.ai-dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes ai-pulse {
  0%, 80%, 100% { opacity: 0.3; transform: scale(0.85); }
  40% { opacity: 1; transform: scale(1); }
}

/* ─── STREAK FLAME ─── */
.streak-flame {
  font-size: 2.5rem;
  line-height: 1;
  filter: drop-shadow(0 0 8px rgba(255,161,22,0.5));
}

/* ─── DIFFICULTY RING ─── */
.difficulty-ring-wrap { position: relative; display: inline-flex; }
.difficulty-ring-label {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
}

/* ─── CATEGORY BARS ─── */
.category-bar-item {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.625rem 0;
}
.category-bar-name {
  font-size: 0.8125rem; color: var(--on-surface-variant);
  min-width: 7rem; flex-shrink: 0;
}
.category-bar-track { flex: 1; height: 5px; background: var(--surface-container-lowest); border-radius: 3px; overflow: hidden; }
.category-bar-fill { height: 100%; border-radius: 3px; transition: width 1s var(--ease); }
.category-bar-count { font-size: 0.75rem; color: var(--outline); min-width: 2.5rem; text-align: right; }

/* ─── LEADERBOARD ROWS ─── */
.leaderboard-row {
  display: flex; align-items: center; gap: 1rem;
  padding: 0.875rem 1rem;
  border-radius: var(--radius-lg);
  transition: background var(--dur-fast) var(--ease);
}
.leaderboard-row:hover { background: var(--surface-container-high); }
.leaderboard-rank {
  font-family: 'Manrope', sans-serif;
  font-size: 0.875rem; font-weight: 800;
  color: var(--on-surface-variant);
  min-width: 1.5rem; text-align: center;
}
.leaderboard-rank.top-1 { color: #ffd700; }
.leaderboard-rank.top-2 { color: #c0c0c0; }
.leaderboard-rank.top-3 { color: #cd7f32; }
.leaderboard-avatar {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--radius-full);
  background: var(--secondary-container);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.875rem; font-weight: 700;
  color: var(--on-secondary-container);
  flex-shrink: 0;
}
.leaderboard-info { flex: 1; min-width: 0; }
.leaderboard-name { font-size: 0.875rem; font-weight: 600; color: var(--on-surface); }
.leaderboard-sub  { font-size: 0.75rem; color: var(--on-surface-variant); }
.leaderboard-score { font-family: 'Manrope', sans-serif; font-size: 0.9375rem; font-weight: 800; color: var(--primary); }

/* ─── DAILY PLANNER ─── */
.plan-problem-item {
  display: flex; align-items: center; gap: 0.875rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(84,68,52,0.08);
}
.plan-problem-item:last-child { border-bottom: none; }
.plan-topic-header {
  font-size: 0.6875rem; font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--outline);
  padding: 1rem 0 0.5rem;
}

/* ─── SUPPORT HUB ─── */
.faq-item {
  border-radius: var(--radius-lg);
  border: 1px solid rgba(84,68,52,0.1);
  overflow: hidden;
  margin-bottom: 0.5rem;
}
.faq-question {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1rem 1.25rem;
  cursor: pointer;
  font-size: 0.875rem; font-weight: 600;
  color: var(--on-surface);
  background: var(--surface-container);
  transition: background var(--dur-fast) var(--ease);
}
.faq-question:hover { background: var(--surface-container-high); }
.faq-answer {
  padding: 0 1.25rem;
  font-size: 0.875rem;
  color: var(--on-surface-variant);
  line-height: 1.65;
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--dur-med) var(--ease), padding var(--dur-med) var(--ease);
}
.faq-item.open .faq-answer {
  max-height: 10rem;
  padding: 0.75rem 1.25rem 1rem;
}
.faq-icon { transition: transform var(--dur-med) var(--ease); color: var(--outline); }
.faq-item.open .faq-icon { transform: rotate(45deg); color: var(--primary-container); }

/* ─── GRID LAYOUTS ─── */
.grid { display: grid; }
.grid-1 { grid-template-columns: 1fr; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.col-span-2 { grid-column: span 2; }
.col-span-3 { grid-column: span 3; }

/* ─── PAGE TRANSITIONS ─── */
.page { display: none; }
.page.active { display: block; }

.page-enter {
  animation: page-in var(--dur-slow) var(--ease) forwards;
}
@keyframes page-in {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ─── HERO SECTION ─── */
.hero-greeting {
  font-family: 'Manrope', sans-serif;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.05;
  color: var(--on-surface);
}
.hero-name { color: var(--primary-container); }
.hero-sub {
  font-size: 1rem;
  color: var(--on-surface-variant);
  font-weight: 300;
  line-height: 1.6;
  max-width: 32rem;
}

/* ─── TOOLTIP ─── */
[data-tooltip] { position: relative; }
[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 6px); left: 50%;
  transform: translateX(-50%);
  background: var(--surface-container-highest);
  color: var(--on-surface);
  font-size: 0.75rem;
  padding: 0.375rem 0.625rem;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease);
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
  z-index: 50;
}
[data-tooltip]:hover::after { opacity: 1; }

/* ─── SHIMMER SKELETON ─── */
.skeleton {
  background: linear-gradient(90deg,
    var(--surface-container) 25%,
    var(--surface-container-high) 50%,
    var(--surface-container) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-md);
}
.loading-skeleton-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1rem;
  border: 1px solid rgba(84, 68, 52, 0.12);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.01);
}
.loading-skeleton-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* ─── NOTIFICATION BADGE ─── */
.notif-badge {
  position: absolute; top: -2px; right: -2px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--primary-container);
  box-shadow: 0 0 6px rgba(255,161,22,0.6);
}

/* ─── PROFILE PAGE ─── */
.profile-banner {
  height: 10rem;
  background: linear-gradient(135deg,
    rgba(255,161,22,0.15) 0%,
    rgba(148,219,255,0.05) 100%
  );
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  position: relative;
  overflow: hidden;
}
.profile-banner::after {
  content: '';
  position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffa116' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.profile-avatar-wrap {
  position: absolute; bottom: -2.5rem; left: 2rem;
}
.profile-avatar {
  width: 5rem; height: 5rem;
  border-radius: var(--radius-full);
  background: var(--secondary-container);
  border: 3px solid var(--surface-container);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.75rem; font-weight: 700;
  color: var(--on-secondary-container);
  font-family: 'Manrope', sans-serif;
}

/* ─── ANALYTICS CHARTS ─── */
.chart-container { width: 100%; position: relative; }
.bar-group { display: flex; align-items: flex-end; gap: 3px; height: 80px; }
.bar {
  flex: 1; border-radius: 3px 3px 0 0;
  background: linear-gradient(180deg, var(--primary-container) 0%, rgba(255,161,22,0.4) 100%);
  transition: height 0.6s var(--ease), opacity var(--dur-fast) var(--ease);
  min-height: 3px;
}
.bar:hover { opacity: 0.8; }
.bar.tertiary {
  background: linear-gradient(180deg, var(--tertiary) 0%, rgba(148,219,255,0.3) 100%);
}
.chart-x-labels {
  display: flex; justify-content: space-between;
  font-size: 0.6875rem; color: var(--outline);
  margin-top: 0.375rem;
  padding: 0 1px;
}

/* ─── ACTIVITY HEATMAP ─── */
.heatmap-grid { display: flex; gap: 3px; }
.heatmap-col { display: flex; flex-direction: column; gap: 3px; }
.heatmap-cell {
  width: 12px; height: 12px;
  border-radius: 2px;
  background: var(--surface-container-lowest);
  transition: background var(--dur-fast) var(--ease);
  cursor: pointer;
}
.heatmap-cell[data-level="1"] { background: rgba(255,161,22,0.2); }
.heatmap-cell[data-level="2"] { background: rgba(255,161,22,0.4); }
.heatmap-cell[data-level="3"] { background: rgba(255,161,22,0.65); }
.heatmap-cell[data-level="4"] { background: rgba(255,161,22,0.9); }

/* ─── FILTER PILLS ─── */
.filter-pills { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.filter-pill {
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-full);
  font-size: 0.8125rem; font-weight: 600;
  color: var(--on-surface-variant);
  background: rgba(84,68,52,0.15);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
  white-space: nowrap;
}
.filter-pill:hover { background: rgba(84,68,52,0.25); color: var(--on-surface); }
.filter-pill.active {
  background: rgba(255,161,22,0.12);
  border-color: rgba(255,161,22,0.25);
  color: var(--primary-container);
}

/* ─── LOADING SPINNER ─── */
.spinner {
  width: 1.5rem; height: 1.5rem;
  border: 2px solid rgba(255,161,22,0.2);
  border-top-color: var(--primary-container);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ─── EMPTY STATE ─── */
.empty-state {
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: 4rem 2rem;
  text-align: center;
  gap: 1rem;
}
.empty-state-icon { font-size: 3rem; color: var(--outline-variant); }
.empty-state-title { font-size: 1rem; font-weight: 700; color: var(--on-surface-variant); font-family: 'Manrope', sans-serif; }
.empty-state-sub { font-size: 0.875rem; color: var(--outline); }

/* ─── GLOW DIVIDER ─── */
.glow-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,161,22,0.2), transparent);
  margin: 2rem 0;
}

/* ═══════════════════════════════════════════════════
   RESPONSIVE
═══════════════════════════════════════════════════ */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(calc(-1 * var(--sidebar-w)));
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: 20px 0 60px rgba(0,0,0,0.5);
  }
  .main-content {
    margin-left: 0;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
  .topbar-nav { display: none; }
  .topbar-tagline { display: block; }
  .hamburger-btn { display: flex; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --topbar-h: 4rem; }
  .main-content { padding-left: 1rem; padding-right: 1rem; padding-top: calc(var(--topbar-h) + 1.5rem); }
  .hero-greeting { font-size: 2rem; }
  .stat-value { font-size: 2.5rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .col-span-2, .col-span-3 { grid-column: span 1; }
  .topbar { padding: 0 1rem; }
}

@media (max-width: 480px) {
  .btn-lg { padding: 0.875rem 1.5rem; }
  .card, .card-low { padding: 1.25rem; }
  .stat-card { padding: 1.25rem; }
}

/* ─── LOGIN / AUTH PAGE ─── */
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: var(--surface);
  background-image:
    radial-gradient(ellipse at 0% 0%, rgba(255,161,22,0.06) 0%, transparent 45%),
    radial-gradient(ellipse at 100% 100%, rgba(148,219,255,0.03) 0%, transparent 45%);
}
.auth-card {
  width: 100%;
  max-width: 75rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--surface-container);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(84,68,52,0.12);
  overflow: hidden;
  box-shadow: 0 40px 80px rgba(0,0,0,0.5);
}
.auth-left {
  background: var(--surface-container-low);
  padding: 3rem;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}
.auth-left::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffa116' fill-opacity='0.035'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}
.auth-left-glow {
  position: absolute; bottom: -4rem; right: -4rem;
  width: 20rem; height: 20rem;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255,161,22,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.auth-right {
  padding: 3rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
@media (max-width: 768px) {
  .auth-card { grid-template-columns: 1fr; }
  .auth-left { display: none; }
}

/* ─── FEATURE PILL ─── */
.feature-pill {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.5rem 0.875rem;
  background: rgba(84,68,52,0.2);
  border: 1px solid rgba(84,68,52,0.25);
  border-radius: var(--radius-full);
  font-size: 0.8125rem; color: var(--on-surface-variant);
}
.feature-pill .material-symbols-outlined { font-size: 1rem; color: var(--primary-container); }

/* ═══════════════════════════════════════════════════
   SUITS v2 — PATCH & ENHANCEMENTS
═══════════════════════════════════════════════════ */

/* Topbar nav fix: default hidden on small, shown on large */
@media (min-width: 1025px) {
  .hamburger-btn { display: none !important; }
  .topbar-tagline { display: none; }
}
@media (max-width: 1024px) {
  .topbar-nav { display: none !important; }
}

/* Topbar dropdown hover */
.dropdown-item:hover {
  background: var(--surface-container-high) !important;
  color: var(--on-surface) !important;
}

/* Topbar dropdown open state */
#topbar-dropdown.open { display: flex !important; }

/* Insights grid responsive */
@media (max-width: 900px) {
  #insights-content > div {
    grid-template-columns: 1fr !important;
  }
}

/* Home page second row responsive */
@media (max-width: 1100px) {
  #page-home .grid[style*="grid-template-columns:1fr 1fr 1fr"] {
    grid-template-columns: 1fr 1fr !important;
  }
}
@media (max-width: 768px) {
  #page-home .grid[style*="grid-template-columns:1fr 1fr 1fr"] {
    grid-template-columns: 1fr !important;
  }
  #page-home .grid[style*="grid-template-columns:repeat(4,1fr)"] {
    grid-template-columns: 1fr 1fr !important;
  }
  #page-home .col-span-2 { grid-column: span 1 !important; }
  #page-dashboard .grid-4 { grid-template-columns: 1fr 1fr !important; }
  #page-dashboard .stat-card.col-span-2 { grid-column: span 2; }
  #page-dashboard .grid-3 { grid-template-columns: 1fr !important; }
  #page-dashboard .grid-2 { grid-template-columns: 1fr !important; }
  #page-profile form { grid-template-columns: 1fr !important; }
  #page-leaderboard .flex[style*="align-items:flex-end"] { display: none; }
  #page-support .grid-2 { grid-template-columns: 1fr !important; }
}
@media (max-width: 480px) {
  #page-home .grid[style*="grid-template-columns:repeat(4,1fr)"] {
    grid-template-columns: 1fr !important;
  }
}

/* Leaderboard "you" row highlight */
.leaderboard-row.you {
  background: rgba(255,161,22,0.07);
  border: 1px solid rgba(255,161,22,0.12);
  border-radius: var(--radius-lg);
}

/* Profile banner pattern enhancement */
.profile-banner {
  background-image:
    linear-gradient(135deg, rgba(255,161,22,0.15) 0%, rgba(148,219,255,0.05) 100%),
    url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffa116' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

/* Problem table responsive */
@media (max-width: 700px) {
  .problems-table th:nth-child(4),
  .problems-table td:nth-child(4) { display: none; }
}

/* Sidebar streak widget */
#sidebar-streak {
  display: block;
  font-family: 'Manrope', sans-serif;
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--primary-container);
  line-height: 1;
}

/* Note modal close button2 alias */
#note-close-btn-2 { display: none; }

/* Page transition smooth */
.page.active {
  display: block;
  animation: page-in var(--dur-slow) var(--ease) forwards;
}

/* Planner solved item style */
.plan-problem-item.solved .problem-title {
  text-decoration: line-through;
  opacity: 0.5;
}
.plan-problem-item.solved { opacity: 0.65; }

/* Admin table row hover */
.admin-table tbody tr:hover td {
  background: rgba(255,255,255,0.02);
}

/* Scrollable page content override */
html, body { height: 100%; overflow-x: hidden; }
.main-content { overflow-y: auto; }

/* Search bar clear on x */
input[type="search"]::-webkit-search-cancel-button { display: none; }

/* Topbar dropdown nav links */
.dropdown-item[data-page] { cursor: pointer; }

/* Active sidebar streak update */
@keyframes streak-pulse {
  0% { text-shadow: 0 0 0 transparent; }
  50% { text-shadow: 0 0 12px rgba(255,161,22,0.6); }
  100% { text-shadow: 0 0 0 transparent; }
}
.streak-flame { animation: streak-pulse 2s ease infinite; }

/* kbd styling for support page */
kbd {
  font-family: 'Inter', monospace;
  font-size: 0.8125rem;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(84,68,52,0.3);
  border-radius: 4px;
  padding: 0.1rem 0.4rem;
  color: var(--on-surface-variant);
}