/* ============================================
   Teachable Machine — Year 7 Unit Website
   Clean, accessible, student-friendly styles
   ============================================ */

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

:root {
  /* Colour palette – friendly classroom look */
  --clr-primary: #2563eb;
  --clr-primary-dark: #1e40af;
  --clr-primary-light: #dbeafe;
  --clr-accent: #f59e0b;
  --clr-accent-light: #fef3c7;
  --clr-success: #16a34a;
  --clr-success-light: #dcfce7;
  --clr-danger: #dc2626;
  --clr-danger-light: #fee2e2;
  --clr-purple: #7c3aed;
  --clr-purple-light: #ede9fe;
  --clr-bg: #f8fafc;
  --clr-surface: #ffffff;
  --clr-text: #1e293b;
  --clr-text-light: #64748b;
  --clr-border: #e2e8f0;
  --clr-sidebar: #1e293b;
  --clr-sidebar-text: #f1f5f9;
  --clr-sidebar-hover: #334155;
  --clr-header: #ffffff;

  /* Typography */
  --font-main: 'Segoe UI', system-ui, -apple-system, Arial, sans-serif;
  --font-mono: 'Consolas', 'Courier New', monospace;
  --fs-base: 18px;
  --fs-small: 0.875rem;
  --fs-h1: 2rem;
  --fs-h2: 1.6rem;
  --fs-h3: 1.3rem;

  /* Layout */
  --sidebar-width: 260px;
  --header-height: 64px;
  --radius: 10px;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);
}

html {
  font-size: var(--fs-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  color: var(--clr-text);
  background: var(--clr-bg);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--clr-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}
a:hover, a:focus {
  color: var(--clr-primary-dark);
}
a:focus-visible {
  outline: 3px solid var(--clr-accent);
  outline-offset: 2px;
  border-radius: 3px;
}

img { max-width: 100%; height: auto; }

/* --- Skip link (accessibility) --- */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--clr-primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 9999;
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus {
  top: 0;
}

/* ==================
   HEADER
   ================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--clr-header);
  border-bottom: 2px solid var(--clr-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.25rem 0 calc(var(--sidebar-width) + 1.25rem);
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.header-left h1 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--clr-text);
  white-space: nowrap;
}

.header-left .badge {
  background: var(--clr-accent-light);
  color: #92400e;
  font-size: var(--fs-small);
  font-weight: 600;
  padding: 0.15rem 0.6rem;
  border-radius: 20px;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Hamburger (mobile) */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
}
.menu-toggle svg {
  width: 28px;
  height: 28px;
  stroke: var(--clr-text);
}

/* Mode toggle */
.mode-toggle {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: var(--fs-small);
  font-weight: 600;
  color: var(--clr-text-light);
}
.mode-toggle label {
  cursor: pointer;
  user-select: none;
}
.toggle-switch {
  position: relative;
  width: 44px;
  height: 24px;
}
.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.toggle-switch .slider {
  position: absolute;
  inset: 0;
  background: var(--clr-border);
  border-radius: 24px;
  transition: 0.25s;
  cursor: pointer;
}
.toggle-switch .slider::before {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 18px;
  height: 18px;
  background: #fff;
  border-radius: 50%;
  transition: 0.25s;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.toggle-switch input:checked + .slider {
  background: var(--clr-purple);
}
.toggle-switch input:checked + .slider::before {
  transform: translateX(20px);
}
.toggle-switch input:focus-visible + .slider {
  outline: 3px solid var(--clr-accent);
  outline-offset: 2px;
}

/* Progress indicator in header */
.progress-bar-mini {
  width: 120px;
  height: 8px;
  background: var(--clr-border);
  border-radius: 8px;
  overflow: hidden;
}
.progress-bar-mini .fill {
  height: 100%;
  background: var(--clr-success);
  border-radius: 8px;
  transition: width 0.4s ease;
}

/* ==================
   SIDEBAR
   ================== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--clr-sidebar);
  color: var(--clr-sidebar-text);
  overflow-y: auto;
  z-index: 200;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease;
}

.sidebar-brand {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.sidebar-brand .logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: #fff;
}
.sidebar-brand .logo svg {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}
.sidebar-brand .logo-text {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.2;
}
.sidebar-brand .logo-sub {
  font-size: 0.7rem;
  color: var(--clr-text-light);
  font-weight: 400;
}

.sidebar-nav {
  flex: 1;
  padding: 0.75rem 0;
}
.sidebar-nav ul {
  list-style: none;
}
.nav-section-title {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.4);
  padding: 1rem 1.25rem 0.4rem;
  font-weight: 600;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 1.25rem;
  color: var(--clr-sidebar-text);
  text-decoration: none;
  font-size: 0.9rem;
  border-left: 3px solid transparent;
  transition: background 0.15s, border-color 0.15s;
}
.sidebar-nav a:hover,
.sidebar-nav a:focus {
  background: var(--clr-sidebar-hover);
}
.sidebar-nav a.active {
  background: var(--clr-sidebar-hover);
  border-left-color: var(--clr-accent);
  font-weight: 600;
}
.sidebar-nav a svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.7;
}
.sidebar-nav a .check {
  margin-left: auto;
  color: var(--clr-success);
  font-size: 0.85rem;
  font-weight: 700;
}

.sidebar-footer {
  padding: 1rem 1.25rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.75rem;
  color: rgba(255,255,255,0.4);
  text-align: center;
}

/* Overlay for mobile */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 150;
}

/* ==================
   MAIN CONTENT
   ================== */
.main-content {
  margin-left: var(--sidebar-width);
  margin-top: var(--header-height);
  padding: 2rem 2.5rem 3rem;
  max-width: 900px;
  flex: 1;
}

/* ==================
   TYPOGRAPHY
   ================== */
h1 { font-size: var(--fs-h1); font-weight: 800; line-height: 1.25; margin-bottom: 0.75rem; }
h2 { font-size: var(--fs-h2); font-weight: 700; line-height: 1.3; margin-top: 2rem; margin-bottom: 0.6rem; }
h3 { font-size: var(--fs-h3); font-weight: 700; margin-top: 1.5rem; margin-bottom: 0.5rem; }
p  { margin-bottom: 1rem; }
ul, ol { margin-bottom: 1rem; padding-left: 1.5rem; }
li { margin-bottom: 0.35rem; }

/* ==================
   CARDS & BOXES
   ================== */
.card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

/* Coloured info boxes */
.box {
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
  border-left: 5px solid;
}
.box-blue    { background: var(--clr-primary-light); border-color: var(--clr-primary); }
.box-yellow  { background: var(--clr-accent-light);  border-color: var(--clr-accent);  }
.box-green   { background: var(--clr-success-light); border-color: var(--clr-success); }
.box-red     { background: var(--clr-danger-light);   border-color: var(--clr-danger);  }
.box-purple  { background: var(--clr-purple-light);  border-color: var(--clr-purple);  }
.box h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Lesson header banner */
.lesson-banner {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-purple));
  color: #fff;
  border-radius: var(--radius);
  padding: 1.5rem 2rem;
  margin-bottom: 2rem;
}
.lesson-banner h1 {
  color: #fff;
  margin-bottom: 0.25rem;
}
.lesson-banner .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: var(--fs-small);
  opacity: 0.9;
  margin-bottom: 0.75rem;
}
.lesson-banner .meta span {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}
.lesson-banner .outcomes {
  list-style: none;
  padding: 0;
}
.lesson-banner .outcomes li {
  padding-left: 1.4rem;
  position: relative;
  margin-bottom: 0.3rem;
}
.lesson-banner .outcomes li::before {
  content: '✓';
  position: absolute;
  left: 0;
  font-weight: 700;
}

/* ==================
   VOCAB LIST
   ================== */
.vocab-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}
.vocab-item {
  background: var(--clr-primary-light);
  border-radius: 8px;
  padding: 0.6rem 0.9rem;
}
.vocab-item strong {
  color: var(--clr-primary-dark);
  display: block;
  font-size: 0.95rem;
}
.vocab-item span {
  font-size: var(--fs-small);
  color: var(--clr-text-light);
}

/* ==================
   STEPS (numbered instructions)
   ================== */
.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
}
.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 3rem;
  margin-bottom: 1.25rem;
  min-height: 2rem;
}
.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 2.2rem;
  height: 2.2rem;
  background: var(--clr-primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
}

/* ==================
   TABLES (results)
   ================== */
.results-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}
.results-table th,
.results-table td {
  border: 2px solid var(--clr-border);
  padding: 0.6rem 0.75rem;
  text-align: left;
}
.results-table th {
  background: var(--clr-primary-light);
  font-weight: 700;
  color: var(--clr-primary-dark);
}
.results-table input[type="text"],
.results-table input[type="number"] {
  width: 100%;
  border: 1px solid var(--clr-border);
  border-radius: 6px;
  padding: 0.35rem 0.5rem;
  font-size: 0.9rem;
  font-family: var(--font-main);
}
.results-table input:focus {
  outline: 2px solid var(--clr-primary);
  border-color: var(--clr-primary);
}

/* ==================
   FORMS / INPUTS
   ================== */
.form-group {
  margin-bottom: 1rem;
}
.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.3rem;
}
.form-group input[type="text"],
.form-group textarea {
  width: 100%;
  border: 2px solid var(--clr-border);
  border-radius: 8px;
  padding: 0.5rem 0.75rem;
  font-size: 1rem;
  font-family: var(--font-main);
  line-height: 1.5;
  transition: border-color 0.15s;
}
.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
  box-shadow: 0 0 0 3px var(--clr-primary-light);
}
.form-group textarea {
  min-height: 80px;
  resize: vertical;
}

/* ==================
   BUTTONS
   ================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.1rem;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-main);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, transform 0.1s;
}
.btn:active { transform: scale(0.97); }
.btn:focus-visible { outline: 3px solid var(--clr-accent); outline-offset: 2px; }

.btn-primary   { background: var(--clr-primary); color: #fff; }
.btn-primary:hover { background: var(--clr-primary-dark); color: #fff; }
.btn-success   { background: var(--clr-success); color: #fff; }
.btn-success:hover { background: #15803d; color: #fff; }
.btn-danger    { background: var(--clr-danger); color: #fff; }
.btn-danger:hover  { background: #b91c1c; color: #fff; }
.btn-outline   { background: transparent; border: 2px solid var(--clr-border); color: var(--clr-text); }
.btn-outline:hover { background: var(--clr-bg); border-color: var(--clr-text-light); }
.btn-small     { padding: 0.35rem 0.75rem; font-size: var(--fs-small); }

/* Done / Mark complete */
.btn-done {
  background: var(--clr-success-light);
  color: var(--clr-success);
  border: 2px solid var(--clr-success);
}
.btn-done.completed {
  background: var(--clr-success);
  color: #fff;
}

/* ==================
   DOWNLOAD CARDS
   ================== */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}
.download-card {
  background: var(--clr-surface);
  border: 2px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.download-card:hover {
  border-color: var(--clr-primary);
  box-shadow: var(--shadow-lg);
}
.download-card svg {
  width: 48px;
  height: 48px;
  margin-bottom: 0.75rem;
  color: var(--clr-primary);
}
.download-card h3 {
  margin-top: 0;
  font-size: 1.05rem;
}
.download-card p {
  font-size: var(--fs-small);
  color: var(--clr-text-light);
  margin-bottom: 0.75rem;
}

/* ==================
   PROGRESS TRACKER
   ================== */
.progress-overview {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-bottom: 2rem;
}
.progress-card {
  background: var(--clr-surface);
  border: 2px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1rem;
  text-align: center;
  text-decoration: none;
  color: var(--clr-text);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.progress-card:hover {
  border-color: var(--clr-primary);
  box-shadow: var(--shadow);
  text-decoration: none;
}
.progress-card.done {
  border-color: var(--clr-success);
  background: var(--clr-success-light);
}
.progress-card .lesson-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--clr-primary);
  line-height: 1;
}
.progress-card.done .lesson-num {
  color: var(--clr-success);
}
.progress-card .lesson-title {
  font-size: var(--fs-small);
  margin-top: 0.25rem;
  color: var(--clr-text-light);
}
.progress-card .status-icon {
  margin-top: 0.5rem;
  font-size: 1.2rem;
}

/* ==================
   EXIT TICKET
   ================== */
.exit-ticket {
  background: var(--clr-accent-light);
  border: 2px solid var(--clr-accent);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 2rem 0;
}
.exit-ticket h3 {
  margin-top: 0;
  color: #92400e;
}

/* ==================
   TEACHER NOTES (hidden by default)
   ================== */
.teacher-only {
  display: none;
  background: var(--clr-purple-light);
  border: 2px dashed var(--clr-purple);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 1rem 0;
}
.teacher-only::before {
  content: '👩‍🏫 Teacher Note';
  display: block;
  font-weight: 700;
  color: var(--clr-purple);
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}
body.teacher-mode .teacher-only {
  display: block;
}

/* ==================
   GLOSSARY
   ================== */
.glossary-list {
  list-style: none;
  padding: 0;
}
.glossary-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--clr-border);
}
.glossary-list dt {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--clr-primary-dark);
}
.glossary-list dd {
  margin: 0.25rem 0 0 0;
  color: var(--clr-text-light);
}

/* ==================
   NAV BUTTONS (prev / next)
   ================== */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--clr-border);
}

/* ==================
   HOME PAGE HERO
   ================== */
.hero {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-purple));
  color: #fff;
  border-radius: var(--radius);
  padding: 2rem 2.5rem;
  margin-bottom: 2rem;
}
.hero h1 { color: #fff; font-size: 2.2rem; }
.hero p  { font-size: 1.1rem; opacity: 0.95; }

/* ==================
   RESPONSIVE
   ================== */
@media (max-width: 900px) {
  :root { --sidebar-width: 0px; }

  .sidebar {
    transform: translateX(-280px);
    width: 280px;
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .sidebar-overlay.open {
    display: block;
  }

  .site-header {
    padding-left: 1rem;
  }

  .menu-toggle {
    display: block;
  }

  .main-content {
    margin-left: 0;
    padding: 1.5rem 1rem 2rem;
  }
}

@media (max-width: 500px) {
  html { font-size: 16px; }
  .hero { padding: 1.25rem; }
  .lesson-banner { padding: 1rem 1.25rem; }
  .download-grid { grid-template-columns: 1fr; }
  .vocab-list { grid-template-columns: 1fr; }
}

/* ==================
   PRINT STYLES
   ================== */
@media print {
  .sidebar,
  .site-header,
  .menu-toggle,
  .sidebar-overlay,
  .btn-done,
  .btn-danger,
  .lesson-nav,
  .mode-toggle,
  .progress-bar-mini,
  .teacher-only,
  .skip-link {
    display: none !important;
  }

  .main-content {
    margin: 0;
    padding: 0.5cm;
    max-width: 100%;
  }

  body {
    font-size: 12pt;
    line-height: 1.5;
    color: #000;
    background: #fff;
  }

  .lesson-banner {
    background: #eee !important;
    color: #000 !important;
    border: 2px solid #333;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
  .lesson-banner h1 { color: #000 !important; }

  .card, .box, .exit-ticket {
    border: 1px solid #999;
    break-inside: avoid;
  }

  .results-table input {
    border: 1px solid #ccc;
    min-height: 1.5em;
  }

  a { color: #000; text-decoration: underline; }
  a::after { content: ' (' attr(href) ')'; font-size: 0.8em; }
  .sidebar-nav a::after,
  .lesson-nav a::after { content: ''; }

  h2, h3 { break-after: avoid; }
}