/* ================================================================ */
/*   IIUCCPS LADDER — COMPETITIVE PROGRAMMER'S DARK UI v2           */
/*   Palette: Space Black + Electric Cyan + Neon Green              */
/* ================================================================ */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700;800&family=Inter:wght@400;500;600&display=swap');

/* ================================================================ */
/*   1. THEME TOKENS                                                  */
/* ================================================================ */
:root {
  --bg-base:       #060d1a;
  --bg-surface:    #0c1627;
  --bg-elevated:   #111e35;
  --bg-card:       rgba(13, 22, 40, 0.88);

  --text-primary:   #e8f1ff;
  --text-secondary: #7b90b2;
  --text-muted:     #465a78;

  --cyan:           #00d4ff;
  --green:          #00ff88;
  --amber:          #ffb800;
  --red:            #ff4d6a;
  --purple:         #a855f7;

  --accent-primary: var(--cyan);
  --accent-green:   var(--green);
  --accent-yellow:  var(--amber);
  --accent-red:     var(--red);

  --border-subtle:  rgba(0, 212, 255, 0.08);
  --border-mid:     rgba(0, 212, 255, 0.18);
  --border-bright:  rgba(0, 212, 255, 0.42);

  --glow-cyan:      0 0 20px rgba(0, 212, 255, 0.35);
  --glow-green:     0 0 20px rgba(0, 255, 136, 0.35);
  --glow-amber:     0 0 20px rgba(255, 184, 0, 0.35);

  --shadow-sm:   0 2px 8px rgba(0,0,0,0.4);
  --shadow-md:   0 4px 20px rgba(0,0,0,0.5);
  --shadow-lg:   0 8px 40px rgba(0,0,0,0.6);

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  16px;
  --radius-xl:  22px;

  --font-brand: 'Space Grotesk', sans-serif;
  --font-body:  'Inter', sans-serif;

  --transition: 0.2s ease;
  --transition-slow: 0.4s ease;
}

body.light-mode {
  --bg-base:        #f0f4fc;
  --bg-surface:     #ffffff;
  --bg-elevated:    #e6ecf7;
  --bg-card:        rgba(255,255,255,0.92);

  --text-primary:   #0d1b30;
  --text-secondary: #4a607e;
  --text-muted:     #8a9db8;

  --cyan:           #0095b8;
  --green:          #00a85a;
  --amber:          #c98000;
  --red:            #d63050;

  --border-subtle:  rgba(0, 149, 184, 0.10);
  --border-mid:     rgba(0, 149, 184, 0.22);
  --border-bright:  rgba(0, 149, 184, 0.45);

  --glow-cyan:      0 0 16px rgba(0, 149, 184, 0.2);
  --glow-green:     0 0 16px rgba(0, 168, 90, 0.2);
  --glow-amber:     0 0 16px rgba(201, 128, 0, 0.2);

  --shadow-sm:   0 2px 8px rgba(0,0,0,0.08);
  --shadow-md:   0 4px 20px rgba(0,0,0,0.10);
  --shadow-lg:   0 8px 40px rgba(0,0,0,0.14);
}


/* ================================================================ */
/*   2. RESET & BASE                                                  */
/* ================================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background-color: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  transition: background-color var(--transition-slow), color var(--transition-slow);
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(0,212,255,0.07) 0%, transparent 65%),
    linear-gradient(var(--border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-subtle) 1px, transparent 1px);
  background-size: 100% 100%, 40px 40px, 40px 40px;
}
body.light-mode {
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(0,149,184,0.05) 0%, transparent 65%),
    linear-gradient(var(--border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-subtle) 1px, transparent 1px);
  background-size: 100% 100%, 40px 40px, 40px 40px;
}
a { color: inherit; text-decoration: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 28px 20px;
}
.hidden { display: none !important; }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--border-mid); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-bright); }


/* ================================================================ */
/*   3. NAVBAR                                                        */
/* ================================================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: 999;
  background: rgba(6, 13, 26, 0.78);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-mid);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition-slow);
}
body.light-mode .navbar { background: rgba(240, 244, 252, 0.86); }

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
  height: 62px;
  display: flex;
  align-items: center;
  gap: 20px;
}

/* Brand */
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.logo-img {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  object-fit: contain;
  filter: drop-shadow(0 0 5px var(--cyan));
}
.nav-brand h1 {
  font-family: var(--font-brand);
  font-size: 1.15rem;
  font-weight: 700;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--green) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

/* Nav links */
.nav-menu {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 1;
  justify-content: center;
}
.nav-link {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.88rem;
  color: var(--text-secondary);
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}
.nav-link:hover {
  color: var(--text-primary);
  background: var(--border-subtle);
}
.nav-link.active {
  color: var(--cyan);
  background: rgba(0, 212, 255, 0.1);
}
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--green));
  border-radius: 99px;
}
.nav-link i { font-size: 0.8rem; }

/* Nav right: theme + search */
.nav-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

/* Theme switcher (compact, in navbar) */
.theme-switcher {
  position: relative;
  width: 54px;
  height: 26px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  border-radius: 99px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding: 0 5px;
  flex-shrink: 0;
  transition: border-color var(--transition);
}
.theme-switcher:hover { border-color: var(--border-bright); }
.theme-switcher .fa-moon { color: #c4a7e7; font-size: 0.72rem; z-index: 1; }
.theme-switcher .fa-sun  { color: var(--amber); font-size: 0.72rem; z-index: 1; }
.theme-toggle-label {
  position: absolute;
  top: 50%;
  left: 3px;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--cyan), var(--green));
  box-shadow: 0 0 8px rgba(0,212,255,0.5);
  cursor: pointer;
  z-index: 2;
  transition: transform var(--transition-slow);
}
#theme-toggle-checkbox:checked ~ .theme-toggle-label {
  transform: translateY(-50%) translateX(27px);
}
#theme-toggle-checkbox { opacity: 0; position: absolute; width: 0; height: 0; }

/* Handle search in navbar */
.handle-search.nav-search {
  display: flex;
  align-items: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.handle-search.nav-search:focus-within {
  border-color: var(--cyan);
  box-shadow: var(--glow-cyan);
}
#cf-handle-input {
  background: transparent;
  border: none;
  color: var(--text-primary);
  padding: 8px 14px;
  font-size: 0.875rem;
  font-family: var(--font-body);
  outline: none;
  width: 160px;
}
#cf-handle-input::placeholder { color: var(--text-muted); }
#search-btn {
  background: linear-gradient(135deg, var(--cyan), var(--green));
  border: none;
  color: #060d1a;
  padding: 0 14px;
  height: 36px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 700;
  transition: opacity var(--transition);
  display: flex;
  align-items: center;
}
#search-btn:hover { opacity: 0.85; }


/* ================================================================ */
/*   4. HERO STRIP (Three.js canvas background)                      */
/* ================================================================ */
.hero-strip {
  position: relative;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  height: 72px;
  overflow: hidden;
}
.hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}
.hero-strip-inner {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 28px;
}
.hero-stat {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  white-space: nowrap;
}
.hero-stat i { font-size: 0.78rem; color: var(--cyan); }
.hero-stat strong { color: var(--text-primary); font-weight: 600; }
.hero-tagline {
  margin-left: auto;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-style: italic;
  white-space: nowrap;
}


/* ================================================================ */
/*   5. SECTION HEADERS                                              */
/* ================================================================ */
.section-header {
  margin-bottom: 24px;
}
.section-header h2 {
  font-family: var(--font-brand);
  font-size: 1.65rem;
  font-weight: 800;
  background: linear-gradient(90deg, var(--cyan), var(--green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-header h2 i {
  -webkit-text-fill-color: var(--cyan);
  font-size: 1.3rem;
}
.section-header p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.section-message {
  text-align: center;
  font-size: 0.95rem;
  color: var(--text-secondary);
  padding: 48px 20px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
}


/* ================================================================ */
/*   6. PROBLEMS VIEW — HEADER & RATING NAV                          */
/* ================================================================ */
.main-header {
  margin-bottom: 20px;
}
.rating-nav {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-wrap: wrap;
}
.rating-btn {
  font-family: var(--font-brand);
  font-size: 0.9rem;
  font-weight: 600;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 8px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  letter-spacing: 0.3px;
}
.rating-btn:hover {
  border-color: var(--border-bright);
  color: var(--cyan);
  box-shadow: var(--glow-cyan);
  transform: translateY(-1px);
}
.rating-btn.active {
  background: rgba(0, 212, 255, 0.12);
  border-color: var(--cyan);
  color: var(--cyan);
  box-shadow: var(--glow-cyan);
}


/* ================================================================ */
/*   7. FILTER CONTROLS & TAGS                                        */
/* ================================================================ */
.filter-controls {
  display: flex;
  gap: 24px;
  align-items: center;
  margin-bottom: 14px;
  padding: 11px 16px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}
.toggle-group {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  font-weight: 500;
}
.switch { position: relative; display: inline-block; width: 40px; height: 22px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  border-radius: 99px;
  transition: background var(--transition), border-color var(--transition);
}
.slider::before {
  content: '';
  position: absolute;
  height: 14px; width: 14px;
  left: 3px; bottom: 3px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: transform var(--transition), background var(--transition);
}
input:checked + .slider { background: rgba(0,212,255,0.15); border-color: var(--cyan); }
input:checked + .slider::before { transform: translateX(18px); background: var(--cyan); box-shadow: 0 0 8px rgba(0,212,255,0.6); }

.tags-container {
  display: flex; flex-wrap: wrap; gap: 7px;
  padding: 14px 16px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 14px;
}
.tag-btn {
  font-size: 0.78rem; font-weight: 500;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  color: var(--text-secondary);
  padding: 5px 12px;
  border-radius: 99px;
  cursor: pointer;
  transition: all var(--transition);
}
.tag-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.tag-btn.active {
  background: rgba(0,212,255,0.12);
  border-color: var(--cyan); color: var(--cyan);
  box-shadow: 0 0 10px rgba(0,212,255,0.2);
}


/* ================================================================ */
/*   8. PROBLEM TABLE                                                 */
/* ================================================================ */
.table-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}
.problem-table { width: 100%; border-collapse: collapse; }
.problem-table thead { background: var(--bg-elevated); }
.problem-table th {
  padding: 13px 18px;
  text-align: left;
  font-family: var(--font-brand);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-mid);
}
.problem-table tbody tr {
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition);
  animation: rowFadeIn 0.28s ease both;
}
@keyframes rowFadeIn {
  from { opacity: 0; transform: translateY(5px); }
  to   { opacity: 1; transform: translateY(0); }
}
.problem-table tbody tr:last-child { border-bottom: none; }
.problem-table tbody tr:hover { background: rgba(0,212,255,0.04); }
.problem-table td { padding: 13px 18px; font-size: 0.9rem; white-space: nowrap; }
.problem-table td:nth-child(2) { white-space: normal; }
.problem-table td:first-child {
  color: var(--text-muted);
  font-family: var(--font-brand);
  font-size: 0.8rem;
  font-weight: 600;
  width: 48px;
}
.problem-link {
  color: var(--text-primary);
  font-weight: 500;
  transition: color var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.problem-link::after {
  content: '↗'; font-size: 0.72rem;
  opacity: 0; transform: translateX(-4px);
  transition: opacity var(--transition), transform var(--transition);
  color: var(--cyan);
}
.problem-link:hover { color: var(--cyan); }
.problem-link:hover::after { opacity: 1; transform: translateX(0); }

/* Status badges */
.status-badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 0.78rem; font-weight: 600;
  font-family: var(--font-brand);
  padding: 4px 10px;
  border-radius: 99px;
}
.status-solved   { background: rgba(0,255,136,0.1); color: var(--green); border: 1px solid rgba(0,255,136,0.25); }
.status-attempted { background: rgba(255,184,0,0.1); color: var(--amber); border: 1px solid rgba(255,184,0,0.25); }
.status-unsolved  { background: transparent; color: var(--text-muted); border: 1px solid var(--border-subtle); }
.status-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; }
.status-solved   .status-dot { background: var(--green); animation: pulseGlow 2s ease-in-out infinite; }
.status-attempted .status-dot { background: var(--amber); }
.status-unsolved  .status-dot { background: var(--text-muted); }
@keyframes pulseGlow {
  0%,100% { box-shadow: 0 0 4px var(--green); }
  50%      { box-shadow: 0 0 12px var(--green), 0 0 22px rgba(0,255,136,0.4); }
}
.solve-count { font-family: var(--font-brand); font-size: 0.84rem; color: var(--text-secondary); font-weight: 500; }
.placeholder { text-align: center; color: var(--text-muted); padding: 60px 20px; font-size: 0.95rem; }
.placeholder-icon { font-size: 2.4rem; margin-bottom: 12px; display: block; opacity: 0.35; }
.status-message { text-align: center; margin-top: 14px; color: var(--text-muted); font-size: 0.84rem; }


/* ================================================================ */
/*   9. ANALYTICS SECTION                                            */
/* ================================================================ */
#analytics-container { animation: fadePageIn 0.35s ease both; }
#compare-container   { animation: fadePageIn 0.35s ease both; }
@keyframes fadePageIn {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Profile info card */
.profile-info-card {
  display: none; /* shown by JS when populated */
  gap: 0;
  background: var(--bg-surface);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 20px;
  box-shadow: var(--shadow-md);
}
.profile-info-card:not(:empty) { display: flex; }

.profile-stat-block {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 20px 16px;
  text-align: center;
  border-right: 1px solid var(--border-subtle);
}
.profile-stat-block:last-child { border-right: none; }
.profile-stat-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.9px;
  text-transform: uppercase;
  color: var(--text-muted);
}
.profile-stat-value {
  font-family: var(--font-brand);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
}
.profile-stat-value.handle-val { font-size: 1.1rem; letter-spacing: -0.3px; }

/* Charts grid */
.analytics-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 0;
}

.chart-wrapper {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 22px;
  box-shadow: var(--shadow-md);
  transition: border-color var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
  min-width: 0;          /* CRITICAL: prevents grid child overflow */
  overflow: hidden;
}
.chart-wrapper:hover { border-color: var(--border-mid); }
.chart-wrapper h3 {
  font-family: var(--font-brand);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 7px;
}
.chart-wrapper h3 i { color: var(--cyan); font-size: 0.82rem; }
.chart-canvas-wrap { flex: 1; position: relative; min-height: 200px; min-width: 0; }
.chart-canvas-wrap canvas { max-width: 100%; max-height: 260px; }


/* ================================================================ */
/*   10. HEATMAP                                                      */
/* ================================================================ */
.heatmap-wrapper {
  grid-column: span 2;   /* spans both columns — prevents overflow */
  gap: 0;
}
.heatmap-outer {
  flex: 1;
  overflow-x: auto;
  padding-bottom: 6px;
}
.heatmap-grid {
  display: flex;
  gap: 2px;
  align-items: flex-start;
  width: max-content;    /* lets heatmap scroll internally within its card */
}
.heatmap-col {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.heatmap-cell {
  width: 11px;
  height: 11px;
  border-radius: 2px;
  flex-shrink: 0;
  cursor: default;
  transition: transform var(--transition);
}
.heatmap-cell:hover { transform: scale(1.5); }
.heatmap-cell.level-0 { background: var(--bg-elevated); }
.heatmap-cell.level-1 { background: rgba(0, 212, 255, 0.18); }
.heatmap-cell.level-2 { background: rgba(0, 212, 255, 0.42); }
.heatmap-cell.level-3 { background: rgba(0, 212, 255, 0.70); }
.heatmap-cell.level-4 { background: #00d4ff; box-shadow: 0 0 7px rgba(0,212,255,0.55); }

.heatmap-legend {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-top: 10px;
  font-size: 0.72rem;
  color: var(--text-muted);
}
.heatmap-legend .heatmap-cell { cursor: default; }
.heatmap-legend .heatmap-cell:hover { transform: none; }


/* ================================================================ */
/*   11. COMPARE SECTION                                             */
/* ================================================================ */
.compare-inputs-row {
  display: flex;
  align-items: flex-end;
  gap: 16px;
  flex-wrap: wrap;
  padding: 24px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
}

.compare-handle-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
  min-width: 180px;
}
.compare-handle-group label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}
.compare-handle-group label i { color: var(--cyan); font-size: 0.75rem; }
.compare-handle-group input {
  width: 100%;
  padding: 11px 15px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.92rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.compare-handle-group input:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(0,212,255,0.15);
}

.vs-badge {
  font-family: var(--font-brand);
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--text-muted);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-bottom: 0;
}

.compare-run-btn {
  padding: 11px 26px;
  background: linear-gradient(135deg, var(--cyan), var(--green));
  color: #060d1a;
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 0.95rem;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: opacity var(--transition), transform var(--transition);
  white-space: nowrap;
  flex-shrink: 0;
  align-self: flex-end;
}
.compare-run-btn:hover { opacity: 0.88; transform: translateY(-1px); }
.compare-run-btn:active { transform: scale(0.97); }
.compare-run-btn:disabled { background: var(--bg-elevated); color: var(--text-muted); cursor: not-allowed; transform: none; }

/* Compare stat cards */
.compare-stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 20px;
}
.compare-player-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-md);
}
.compare-player-card.player-a { border-top: 3px solid var(--cyan); }
.compare-player-card.player-b { border-top: 3px solid var(--green); }

.compare-player-handle {
  font-family: var(--font-brand);
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.compare-player-card.player-a .compare-player-handle { color: var(--cyan); }
.compare-player-card.player-b .compare-player-handle { color: var(--green); }

.compare-stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 9px 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.88rem;
}
.compare-stat-row:last-child { border-bottom: none; }
.compare-stat-row .cs-label { color: var(--text-muted); font-weight: 500; }

/* Player A (cyan) — muted cyan for non-winners, full bright for winners */
.compare-player-card.player-a .cs-value        { font-family: var(--font-brand); font-weight: 600; color: rgba(0,212,255,0.5); }
.compare-player-card.player-a .cs-value.winner { color: var(--cyan); font-weight: 700; }

/* Player B (green) — muted green for non-winners, full bright for winners */
.compare-player-card.player-b .cs-value        { font-family: var(--font-brand); font-weight: 600; color: rgba(0,255,136,0.45); }
.compare-player-card.player-b .cs-value.winner { color: var(--green); font-weight: 700; }

/* Rank value: no color override — inherits CF rank class color */
.compare-stat-row .cs-rank-value {
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 0.88rem;
}

.compare-chart-wrapper {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-md);
}
.compare-chart-wrapper h3 {
  font-family: var(--font-brand);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 7px;
}
.compare-chart-wrapper h3 i { color: var(--cyan); }
#compare-history-chart { max-height: 320px; }


/* ================================================================ */
/*   12. CODEFORCES RANK COLORS                                      */
/* ================================================================ */
.rank-newbie                { color: #808080; }
.rank-pupil                 { color: #008000; }
.rank-specialist            { color: #03a89e; }
.rank-expert                { color: #4169e1; }
.rank-candidate-master      { color: #aa00aa; }
.rank-master                { color: #ff8c00; }
.rank-international-master  { color: #ff8c00; }
.rank-grandmaster           { color: #ff3333; }
.rank-international-grandmaster { color: #ff3333; }
.rank-legendary-grandmaster { color: #ff0000; }


/* ================================================================ */
/*   13. MODALS                                                       */
/* ================================================================ */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(6,13,26,0.85);
  backdrop-filter: blur(6px);
  display: flex; justify-content: center; align-items: center;
  z-index: 1000;
  opacity: 0; visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}
.modal-overlay:not(.hidden) { opacity: 1; visibility: visible; }
.modal-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-xl);
  padding: 34px 38px;
  max-width: 560px; width: 90%;
  position: relative;
  box-shadow: var(--shadow-lg), 0 0 60px rgba(0,212,255,0.07);
  transform: scale(0.94) translateY(12px);
  transition: transform 0.32s cubic-bezier(0.34,1.56,0.64,1);
}
.modal-overlay:not(.hidden) .modal-content { transform: scale(1) translateY(0); }
.modal-close-btn {
  position: absolute; top: 12px; right: 14px;
  background: var(--bg-elevated); border: 1px solid var(--border-mid);
  color: var(--text-secondary);
  font-size: 1.15rem; width: 30px; height: 30px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%; cursor: pointer; line-height: 1;
  transition: all var(--transition);
}
.modal-close-btn:hover { background: rgba(255,77,106,0.15); border-color: var(--red); color: var(--red); transform: rotate(90deg); }
.modal-content h2 {
  font-family: var(--font-brand); font-size: 1.45rem; font-weight: 700;
  background: linear-gradient(90deg, var(--cyan), var(--green));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 14px;
}
.modal-content p { color: var(--text-secondary); line-height: 1.65; margin-bottom: 18px; font-size: 0.92rem; }
.modal-content ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.modal-content li {
  color: var(--text-secondary); line-height: 1.5;
  padding: 11px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
}
.modal-content li::before { content: '▸'; color: var(--green); margin-right: 8px; font-weight: bold; }
.modal-content li strong { color: var(--text-primary); font-weight: 600; }


/* ================================================================ */
/*   14. CONTACT FORM                                                 */
/* ================================================================ */
.form-group { margin-bottom: 16px; }
form label { display: block; margin-bottom: 7px; color: var(--text-secondary); font-size: 0.83rem; font-weight: 500; }
form input, form textarea {
  width: 100%; padding: 10px 13px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-mid);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body); font-size: 0.9rem;
  box-sizing: border-box;
  transition: border-color var(--transition), box-shadow var(--transition);
}
form input:focus, form textarea:focus {
  outline: none; border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(0,212,255,0.14);
}
form textarea { resize: vertical; }
.submit-btn {
  width: 100%; padding: 12px;
  background: linear-gradient(135deg, var(--cyan), var(--green));
  color: #060d1a;
  font-family: var(--font-brand); font-weight: 700; font-size: 0.95rem;
  border: none; border-radius: var(--radius-md);
  cursor: pointer;
  transition: opacity var(--transition), transform var(--transition);
}
.submit-btn:hover { opacity: 0.86; transform: translateY(-1px); }
.submit-btn:active { transform: scale(0.98); }
.submit-btn:disabled { background: var(--bg-elevated); color: var(--text-muted); cursor: not-allowed; transform: none; }
.form-status { margin-bottom: 13px; padding: 10px 13px; border-radius: var(--radius-md); text-align: center; font-weight: 500; font-size: 0.88rem; display: none; }
.form-status.success { background: rgba(0,255,136,0.1); color: var(--green); border: 1px solid rgba(0,255,136,0.2); display: block; }
.form-status.error   { background: rgba(255,77,106,0.1); color: var(--red);  border: 1px solid rgba(255,77,106,0.2); display: block; }


/* ================================================================ */
/*   15. TOAST NOTIFICATIONS                                          */
/* ================================================================ */
.toast {
  position: fixed; left: 50%; top: 76px;
  transform: translateX(-50%) translateY(-14px);
  display: flex; align-items: center; gap: 9px;
  padding: 11px 18px;
  border-radius: var(--radius-md);
  font-family: var(--font-body); font-weight: 500; font-size: 0.88rem;
  box-shadow: var(--shadow-lg); z-index: 9999;
  opacity: 0;
  transition: opacity 0.24s ease, transform 0.24s ease;
  backdrop-filter: blur(12px);
  pointer-events: none;
}
.toast.toast-success { background: rgba(0,30,18,0.92); border: 1px solid rgba(0,255,136,0.3); color: var(--green); }
.toast.toast-error   { background: rgba(30,6,12,0.92);  border: 1px solid rgba(255,77,106,0.3); color: var(--red); }
.toast.toast-visible { opacity: 1; transform: translateX(-50%) translateY(0); }


/* ================================================================ */
/*   16. FOOTER                                                       */
/* ================================================================ */
.app-footer {
  margin-top: 60px;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  padding: 28px 20px;
}
.footer-container {
  max-width: 1200px; margin: 0 auto;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 18px;
}
.footer-left h3 {
  font-family: var(--font-brand); font-size: 0.95rem; font-weight: 700;
  background: linear-gradient(90deg, var(--cyan), var(--green));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 3px;
}
.footer-left p { color: var(--text-muted); font-size: 0.8rem; }
.footer-right { display: flex; gap: 14px; align-items: center; }
.footer-right a {
  color: var(--text-muted); font-size: 1.2rem;
  transition: color var(--transition), transform var(--transition), text-shadow var(--transition);
  display: inline-flex;
}
.footer-right a:hover { color: var(--cyan); transform: translateY(-3px); text-shadow: 0 0 12px var(--cyan); }


/* ================================================================ */
/*   17. RESPONSIVE                                                   */
/* ================================================================ */
@media (max-width: 1100px) {
  .nav-brand h1 { display: none; }
  #cf-handle-input { width: 130px; }
}

@media (max-width: 900px) {
  /* Analytics: collapse to 1 column; heatmap no longer needs span-2 */
  .analytics-grid { grid-template-columns: 1fr; }
  .heatmap-wrapper { grid-column: span 1; }

  /* Compare: collapse to 1 column */
  .compare-stats-grid { grid-template-columns: 1fr; }

  /* Nav compaction */
  .nav-menu { gap: 0; }
  .nav-link { padding: 6px 10px; font-size: 0.82rem; }

  /* Profile card: allow 3 per row on medium screens */
  .profile-info-card { flex-wrap: wrap; }
  .profile-stat-block {
    flex: 1 1 calc(33.333% - 1px);
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
    padding: 14px 12px;
  }
  .profile-stat-block:nth-child(3n) { border-right: none; }
}

@media (max-width: 768px) {
  /* Navbar */
  .nav-container {
    flex-wrap: wrap;
    height: auto;
    padding: 10px 14px;
    gap: 8px;
  }
  .nav-brand { order: 1; }
  .nav-right  { order: 2; margin-left: auto; }
  .nav-menu   { order: 3; width: 100%; justify-content: center; border-top: 1px solid var(--border-subtle); padding-top: 8px; }

  /* Hero */
  .hero-strip { height: auto; padding: 10px 0; }
  .hero-strip-inner { flex-wrap: wrap; gap: 8px; padding: 0 14px; }
  .hero-tagline { display: none; }
  .hero-stat { font-size: 0.78rem; }

  /* Containers */
  .container { padding: 18px 14px; }
  .section-header h2 { font-size: 1.35rem; }

  /* Charts */
  .chart-wrapper { padding: 16px; }
  .chart-wrapper h3 { font-size: 0.74rem; margin-bottom: 12px; }
  .chart-canvas-wrap { min-height: 160px; }
  .chart-canvas-wrap canvas { max-height: 200px; }

  /* Profile info: 2 per row on mobile */
  .profile-stat-block { flex: 1 1 calc(50% - 1px); }
  .profile-stat-value { font-size: 1.1rem; }

  /* Compare inputs: handles side-by-side, button wraps below */
  .compare-inputs-row { flex-direction: row; flex-wrap: wrap; padding: 16px; gap: 10px; align-items: flex-end; }
  .compare-handle-group { flex: 1; min-width: 0; }
  .compare-run-btn { flex: 0 0 100%; justify-content: center; }
  .compare-player-card { padding: 16px; }
  .compare-player-handle { font-size: 1.2rem; margin-bottom: 12px; }

  /* Rating nav */
  .rating-nav { gap: 5px; }

  /* Footer */
  .footer-container { flex-direction: column; text-align: center; }

  /* Modal */
  .modal-content { padding: 22px 16px; }

  /* Handle input in navbar */
  #cf-handle-input { width: 110px; }

  /* Compare inputs: keep handles in a row, button wraps to new row */
  .compare-inputs-row { padding: 18px; gap: 10px; flex-wrap: wrap; }
  .compare-handle-group { flex: 1; min-width: 110px; }
  .compare-run-btn { flex: 0 0 100%; justify-content: center; margin-top: 4px; }
  .vs-badge { flex-shrink: 0; }

  /* Compare stat cards */
  .compare-player-card { padding: 16px; border-radius: 14px; }
  .compare-player-handle { font-size: 1.15rem; margin-bottom: 12px; }
  .compare-stat-row { padding: 8px 0; font-size: 0.85rem; }
}

@media (max-width: 480px) {
  /* Navbar */
  #cf-handle-input { width: 82px; font-size: 0.8rem; }
  .nav-link { padding: 5px 8px; font-size: 0.78rem; }
  .nav-link i { display: none; }

  /* Rating buttons */
  .rating-btn { padding: 6px 10px; font-size: 0.8rem; }

  /* Table */
  .problem-table th, .problem-table td { padding: 10px 10px; }
  .problem-table td:nth-child(3) { display: none; }
  .problem-table th:nth-child(3) { display: none; }

  /* Analytics */
  .analytics-grid { gap: 10px; }
  .chart-wrapper { padding: 14px; }
  .chart-canvas-wrap { min-height: 130px; }
  .chart-canvas-wrap canvas { max-height: 160px; }

  /* Profile info */
  .profile-stat-block { flex: 1 1 calc(50% - 1px); padding: 11px 8px; }
  .profile-stat-value { font-size: 0.95rem; }
  .profile-stat-label { font-size: 0.6rem; }

  /* Compare: keep handles side-by-side even on tiny screens */
  .compare-handle-group { flex: 1; min-width: 0; }
  .vs-badge { flex-shrink: 0; align-self: flex-end; margin-bottom: 0; }
  .compare-inputs-row { padding: 14px; gap: 10px; }
  .compare-handle-group input { padding: 9px 12px; font-size: 0.85rem; }
  .compare-player-card { padding: 14px; }
  .compare-stat-row { font-size: 0.8rem; padding: 7px 0; }
  .compare-player-handle { font-size: 1rem; }

  /* Heatmap cells: shrink on very small */
  .heatmap-cell { width: 9px; height: 9px; }
  .heatmap-grid { gap: 2px; }
  .heatmap-col  { gap: 2px; }

  /* Section */
  .section-header h2 { font-size: 1.2rem; }
  .section-message { padding: 28px 14px; }
}