/* ==========================================================================
   Accounting Through Colours — Pure CSS (no Tailwind, no framework)
   ========================================================================== */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Colour system */
  --green:    #16a34a;  --green-bg:    #f0fdf4;  --green-chip:  #dcfce7;  --green-text: #15803d;
  --red:      #dc2626;  --red-bg:      #fef2f2;  --red-chip:    #fee2e2;  --red-text:   #b91c1c;
  --orange:   #ea580c;  --orange-bg:   #fff7ed;  --orange-chip: #ffedd5;  --orange-text:#c2410c;
  --yellow:   #ca8a04;  --yellow-bg:   #fefce8;  --yellow-chip: #fef9c3;  --yellow-text:#a16207;
  --blue:     #2563eb;  --blue-bg:     #eff6ff;  --blue-chip:   #dbeafe;  --blue-text:  #1d4ed8;

  /* Neutrals */
  --slate-50:  #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --white:     #ffffff;

  --radius-sm: 6px;
  --radius:    12px;
  --radius-lg: 16px;

  --shadow-sm:  0 1px 2px rgba(0,0,0,0.05);
  --shadow:     0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg:  0 10px 15px -3px rgba(0,0,0,0.10), 0 4px 6px -4px rgba(0,0,0,0.05);
  --shadow-xl:  0 20px 25px -5px rgba(0,0,0,0.10), 0 8px 10px -6px rgba(0,0,0,0.05);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--slate-800);
  background: var(--slate-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ---------- Loading Screen ---------- */
.loading-screen {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: var(--slate-50);
  color: var(--slate-500);
}
.spinner {
  width: 48px; height: 48px;
  border: 4px solid var(--slate-200);
  border-top-color: var(--green);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Layout helpers ---------- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding-left: 12px;
  padding-right: 12px;
}
@media (min-width: 640px) {
  .container { padding-left: 16px; padding-right: 16px; }
}

.min-h-screen { min-height: 100vh; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-1 { flex: 1; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: 0.5rem; } .gap-3 { gap: 0.75rem; } .gap-4 { gap: 1rem; }

/* ==========================================================================
   HOME PAGE
   ========================================================================== */

.home-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: linear-gradient(135deg, var(--slate-50) 0%, var(--white) 50%, var(--slate-100) 100%);
}

/* Hero header */
.home-hero {
  background: linear-gradient(90deg,
    #7c3aed 0%,    /* Violet */
    #4338ca 14%,   /* Indigo */
    #2563eb 28%,   /* Blue */
    #16a34a 42%,   /* Green */
    #ca8a04 56%,   /* Yellow */
    #ea580c 70%,   /* Orange */
    #dc2626 100%   /* Red */
  );
  color: var(--white);
  box-shadow: var(--shadow-lg);
}
.home-hero .container { padding-top: 2.5rem; padding-bottom: 2.5rem; }
@media (min-width: 640px) { .home-hero .container { padding-top: 3.5rem; padding-bottom: 3.5rem; } }

.home-hero .eyebrow {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.8);
  margin-bottom: 0.5rem;
}
.home-hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.1;
}
@media (min-width: 640px) { .home-hero h1 { font-size: 3rem; } }
@media (min-width: 768px) { .home-hero h1 { font-size: 3.75rem; } }

.home-hero .subtitle {
  margin-top: 0.75rem;
  font-size: 1rem;
  color: rgba(255,255,255,0.9);
  max-width: 42rem;
}
@media (min-width: 640px) { .home-hero .subtitle { font-size: 1.125rem; } }
@media (min-width: 768px) { .home-hero .subtitle { font-size: 1.25rem; } }

.home-hero .actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-lg { padding: 0.75rem 1.5rem; font-size: 1rem; }
.btn-primary {
  background: var(--white);
  color: var(--slate-800);
  font-weight: 600;
}
.btn-primary:hover { background: rgba(255,255,255,0.9); }
.btn-outline-light {
  background: rgba(255,255,255,0.1);
  color: var(--white);
  border-color: rgba(255,255,255,0.4);
}
.btn-outline-light:hover { background: rgba(255,255,255,0.2); }
.btn-ghost { color: var(--white); }
.btn-ghost:hover { background: rgba(255,255,255,0.2); }
.btn-ghost:disabled { opacity: 0.3; cursor: not-allowed; }
.btn-outline {
  background: var(--white);
  border: 1px solid var(--slate-300);
  color: var(--slate-700);
}
.btn-outline:hover { background: var(--slate-50); }
.btn-outline:disabled { opacity: 0.5; cursor: not-allowed; }

/* Progress bar */
.progress-bar-section {
  background: var(--white);
  border-bottom: 1px solid var(--slate-200);
}
.progress-bar-section .container {
  padding-top: 1rem; padding-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.progress-bar-section .icon { color: var(--slate-500); flex-shrink: 0; }
.progress-info { flex: 1; }
.progress-info-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.875rem;
  margin-bottom: 0.25rem;
}
.progress-info-row .label { font-weight: 600; color: var(--slate-700); }
.progress-info-row .count { color: var(--slate-500); }
.progress-track {
  height: 8px;
  background: var(--slate-200);
  border-radius: 999px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--green) 0%, var(--yellow) 50%, var(--blue) 100%);
  transition: width 0.5s ease;
  border-radius: 999px;
}
.progress-percent { font-size: 0.875rem; font-weight: 700; color: var(--slate-700); flex-shrink: 0; }

/* Main content */
.home-main {
  flex: 1;
  padding-top: 2rem; padding-bottom: 3rem;
}
.home-main .container { display: flex; flex-direction: column; gap: 3rem; }

/* Section headers */
.section-header { margin-bottom: 0.5rem; display: flex; align-items: center; gap: 0.5rem; }
.section-header h2 { font-size: 1.5rem; font-weight: 700; color: var(--slate-800); }
@media (min-width: 640px) { .section-header h2 { font-size: 1.875rem; } }
.section-header .icon { color: var(--slate-700); }
.section-desc { color: var(--slate-600); margin-bottom: 1.5rem; max-width: 48rem; }

/* Colour legend grid */
.colour-legend-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}
@media (min-width: 640px) { .colour-legend-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1024px) { .colour-legend-grid { grid-template-columns: repeat(5, 1fr); gap: 1rem; } }

.colour-card {
  background: var(--white);
  border: 1px solid var(--slate-200);
  border-top-width: 4px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
  overflow: hidden;
}
.colour-card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.colour-card-header { padding: 1rem 1rem 0.75rem; }
.colour-card-header .row { display: flex; align-items: center; gap: 0.75rem; }
.colour-swatch {
  width: 40px; height: 40px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
}
.colour-card-title { font-size: 1.125rem; font-weight: 700; }
.colour-card-meaning {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--slate-500);
}
.colour-card-body { padding: 0 1rem 1rem; display: flex; flex-direction: column; gap: 0.5rem; }
.colour-chip {
  display: inline-flex;
  padding: 0.125rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  align-self: flex-start;
}
.colour-card-desc { font-size: 0.75rem; color: var(--slate-600); line-height: 1.5; }
.colour-card-examples { display: flex; flex-wrap: wrap; gap: 0.25rem; padding-top: 0.25rem; }
.example-tag {
  font-size: 0.625rem;
  background: var(--slate-100);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
  color: var(--slate-600);
}

/* Day curriculum grid — 5x2 on desktop */
.day-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}
@media (min-width: 640px) { .day-grid { grid-template-columns: repeat(3, 1fr); gap: 1rem; } }
@media (min-width: 1024px) { .day-grid { grid-template-columns: repeat(5, 1fr); } }

.day-card {
  display: block;
  text-align: left;
  width: 100%;
  background: var(--white);
  border: 2px solid var(--slate-200);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
  overflow: hidden;
}
.day-card:hover { box-shadow: var(--shadow-xl); transform: translateY(-4px); border-color: var(--slate-400); }

.day-card-header {
  padding: 0.75rem 1rem;
  text-align: center;
  color: var(--white);
}
.day-card-header .day-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  opacity: 0.8;
}
.day-card-header .day-number {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  margin-top: 0.25rem;
}
@media (min-width: 640px) { .day-card-header .day-number { font-size: 3.75rem; } }
.day-card-header .day-status {
  display: flex;
  justify-content: center;
  margin-top: 0.5rem;
}

.day-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.125rem 0.5rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(255,255,255,0.25);
  color: var(--white);
}

.day-card-body { padding: 0.75rem 1rem 1rem; }
.day-card-title {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--slate-800);
  line-height: 1.4;
  min-height: 2.5rem;
}
@media (min-width: 640px) { .day-card-title { font-size: 1rem; } }
.day-card-subtitle {
  font-size: 0.75rem;
  color: var(--slate-600);
  line-height: 1.5;
  margin-top: 0.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.day-card-footer {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding-top: 0.5rem;
  margin-top: 0.5rem;
  border-top: 1px solid var(--slate-100);
}
.day-colour-dot { width: 8px; height: 8px; border-radius: 50%; }
.day-colour-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
  font-size: 0.625rem;
  font-weight: 700;
}
.day-colour-pill .dot { width: 6px; height: 6px; border-radius: 50%; }
.day-open-hint {
  margin-left: auto;
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--slate-400);
  display: flex;
  align-items: center;
  gap: 0.125rem;
}
.day-card:hover .day-open-hint { color: var(--slate-700); }

/* Footer */
.footer {
  margin-top: auto;
  background: var(--slate-800);
  color: var(--slate-300);
}
.footer .container {
  padding-top: 1.5rem; padding-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  font-size: 0.875rem;
}
@media (min-width: 640px) { .footer .container { flex-direction: row; } }
.footer .footer-muted { color: var(--slate-400); }

/* ==========================================================================
   DAY PAGE
   ========================================================================== */

.day-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Sticky day header */
.day-header {
  position: sticky;
  top: 0;
  z-index: 20;
  color: var(--white);
  box-shadow: var(--shadow);
}
.day-header .container {
  padding-top: 1rem; padding-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}
.day-header .day-counter {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
}
@media (min-width: 640px) { .day-header .day-counter { font-size: 1rem; } }
.day-header .day-counter .num {
  font-size: 1.5rem;
  font-weight: 800;
}
@media (min-width: 640px) { .day-header .day-counter .num { font-size: 1.875rem; } }
.day-header .day-counter .opacity-80 { opacity: 0.8; }
.day-header .nav-group { display: flex; gap: 0.25rem; }
.day-header .btn-ghost span { display: none; }
@media (min-width: 640px) { .day-header .btn-ghost span { display: inline; } }

/* Day main content */
.day-main {
  flex: 1;
  padding-top: 1.5rem; padding-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.day-main .container { display: flex; flex-direction: column; gap: 2rem; }

/* Day title block */
.day-title-block .eyebrow {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.day-title-block h1 {
  font-size: 1.875rem;
  font-weight: 800;
  color: var(--slate-800);
  margin-top: 0.25rem;
  line-height: 1.15;
}
@media (min-width: 640px) { .day-title-block h1 { font-size: 2.25rem; } }
@media (min-width: 768px) { .day-title-block h1 { font-size: 3rem; } }
.day-title-block .subtitle {
  font-size: 1rem;
  color: var(--slate-600);
  margin-top: 0.5rem;
  max-width: 48rem;
}
@media (min-width: 640px) { .day-title-block .subtitle { font-size: 1.125rem; } }

/* Section heading */
.section-heading {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}
.section-heading h2 { font-size: 1.5rem; font-weight: 700; color: var(--slate-800); }
.section-heading .icon { width: 20px; height: 20px; }

/* Concept paragraphs */
.concept-paragraphs { display: flex; flex-direction: column; gap: 1rem; max-width: none; }
.concept-paragraphs p {
  color: var(--slate-700);
  line-height: 1.7;
  font-size: 1rem;
}
@media (min-width: 640px) { .concept-paragraphs p { font-size: 1.05rem; } }

/* Bullet card */
.bullet-card {
  border: 1px solid var(--slate-200);
  border-left-width: 4px;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.7);
  padding: 1rem;
}
.bullet-card ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.bullet-card li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--slate-700);
}
@media (min-width: 640px) { .bullet-card li { font-size: 1rem; } }
.bullet-card li::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: currentColor;
  margin-top: 0.4rem;
  flex-shrink: 0;
}

/* Images grid */
.images-grid {
  display: grid;
  gap: 0.75rem;
}
@media (min-width: 640px) { .images-grid { gap: 1rem; } }
.images-grid.cols-1 { grid-template-columns: 1fr; }
.images-grid.cols-2 { grid-template-columns: 1fr; }
@media (min-width: 640px) { .images-grid.cols-2 { grid-template-columns: repeat(2, 1fr); } }
.images-grid.cols-3 { grid-template-columns: repeat(2, 1fr); }
@media (min-width: 640px) { .images-grid.cols-3 { grid-template-columns: repeat(3, 1fr); } }
.images-grid.cols-4 { grid-template-columns: repeat(2, 1fr); }
@media (min-width: 640px) { .images-grid.cols-4 { grid-template-columns: repeat(4, 1fr); } }
.images-grid.wide-2 { grid-template-columns: 1fr; }
@media (min-width: 768px) { .images-grid.wide-2 { grid-template-columns: repeat(2, 1fr); } }
.images-grid.wide-3 { grid-template-columns: 1fr; }
@media (min-width: 640px) { .images-grid.wide-3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .images-grid.wide-3 { grid-template-columns: repeat(3, 1fr); } }

.image-figure {
  border: 2px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}
.image-figure:hover { box-shadow: var(--shadow); }
.image-figure img { width: 100%; display: block; }
.image-figure.square img { aspect-ratio: 1 / 1; object-fit: cover; }
.image-figure.wide img { aspect-ratio: 16 / 10; object-fit: cover; }
.image-figure figcaption {
  font-size: 0.75rem;
  color: var(--slate-600);
  padding: 0.625rem 0.75rem;
  text-align: center;
  font-weight: 500;
}
@media (min-width: 640px) {
  .image-figure figcaption { font-size: 0.875rem; padding: 0.75rem; }
}

/* ==========================================================================
   WORKSHEET
   ========================================================================== */

.worksheet-card {
  border: 2px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  overflow: hidden;
}
.worksheet-header {
  padding: 1rem 1.25rem;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem;
}
.worksheet-header .label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.worksheet-header .prompt {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--slate-800);
  margin-top: 0.25rem;
}
@media (min-width: 640px) { .worksheet-header .prompt { font-size: 1.25rem; } }
.worksheet-mode-badge {
  flex-shrink: 0;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
}

.worksheet-body { padding: 1.25rem; display: flex; flex-direction: column; gap: 1rem; }

.options-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}
@media (min-width: 640px) { .options-grid { grid-template-columns: repeat(3, 1fr); } }

.option-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 120px;
  padding: 1rem 1.25rem;
  border: 2px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--slate-700);
  transition: all 0.2s ease;
  position: relative;
}
.option-btn:hover { transform: scale(1.02); border-color: var(--slate-400); background: var(--slate-50); }
.option-btn .emoji { font-size: 2rem; }
@media (min-width: 640px) { .option-btn .emoji { font-size: 2.5rem; } }
.option-btn .label {
  font-size: 0.875rem;
  font-weight: 600;
  text-align: center;
  line-height: 1.3;
}

/* Correct pick — blink in topic colour */
.option-btn.correct {
  animation: blink 0.6s ease-in-out 3;
}
.option-btn.correct .check-badge {
  position: absolute;
  top: -8px; right: -8px;
  background: var(--white);
  border-radius: 50%;
  padding: 2px;
  box-shadow: var(--shadow);
  display: flex;
}

/* Wrong pick — shake */
.option-btn.wrong {
  border-color: var(--red-chip);
  background: var(--red-chip);
  color: var(--red-text);
  animation: shake 0.4s ease-in-out;
}
.option-btn.wrong .x-badge {
  position: absolute;
  top: -8px; right: -8px;
  background: var(--white);
  border-radius: 50%;
  padding: 2px;
  box-shadow: var(--shadow);
  display: flex;
}

@keyframes blink {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.05); }
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

/* Hint box */
.hint-box {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  font-size: 0.875rem;
  color: #92400e;
}

/* Explanation box */
.explanation-box {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  border-radius: var(--radius-sm);
  padding: 1rem;
  font-size: 0.875rem;
  border: 1px solid;
}
.explanation-box .title { font-weight: 700; margin-bottom: 0.25rem; }

/* Worksheet footer */
.worksheet-footer {
  display: flex;
  justify-content: flex-end;
  padding-top: 0.25rem;
}
.reset-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.75rem;
  font-size: 0.875rem;
  color: var(--slate-500);
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}
.reset-btn:hover { background: var(--slate-100); color: var(--slate-700); }

/* Worksheet counter badge */
.worksheet-counter {
  margin-left: auto;
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--slate-300);
  border-radius: 999px;
  font-size: 0.75rem;
  color: var(--slate-600);
  background: var(--white);
}

/* ==========================================================================
   VIDEO EMBED
   ========================================================================== */
.video-card {
  border: 2px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  overflow: hidden;
}
.video-embed {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 */
}
.video-embed iframe {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  border: 0;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem;
  background: var(--slate-50);
  border-top: 1px solid var(--slate-200);
  font-size: 0.875rem;
  color: var(--slate-700);
  font-weight: 500;
}

/* ==========================================================================
   DAY NAVIGATION FOOTER
   ========================================================================== */
.day-nav-footer {
  padding-top: 0.5rem;
  padding-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  border-top: 1px solid var(--slate-200);
  align-items: center;
  justify-content: space-between;
}
@media (min-width: 640px) { .day-nav-footer { flex-direction: row; } }

.completion-status {
  font-size: 0.875rem;
  color: var(--slate-600);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.completion-status.done { color: var(--green); }
.completion-status .done-icon { width: 20px; height: 20px; flex-shrink: 0; }

.nav-buttons {
  display: flex;
  gap: 0.5rem;
  width: 100%;
}
@media (min-width: 640px) { .nav-buttons { width: auto; } }
.nav-buttons .btn { flex: 1; }
@media (min-width: 640px) { .nav-buttons .btn { flex: none; } }

/* ==========================================================================
   UTILITIES
   ========================================================================== */
.fade-in-up { animation: fadeInUp 0.4s ease-out; }
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* SVG icons sizing */
.icon { width: 16px; height: 16px; flex-shrink: 0; }
.icon-sm { width: 14px; height: 14px; }
.icon-lg { width: 20px; height: 20px; }
.icon-xl { width: 24px; height: 24px; }

/* Responsive: smaller screens hide some text */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}