/* LangCraft Global CSS */
/* Design: Dark-first dev learning platform with electric blue + soft amber accents */

:root {
  --blue:     #3b82f6;
  --blue-dim: #1d4ed8;
  --amber:    #f59e0b;
  --green:    #10b981;
  --red:      #ef4444;
  --mono:     'JetBrains Mono', monospace;
  --sans:     'Inter', system-ui, sans-serif;
}

[data-theme="dark"], .dark-theme {
  --bg:        #0d1117;
  --bg2:       #161b22;
  --bg3:       #21262d;
  --border:    #30363d;
  --text:      #e6edf3;
  --text-dim:  #8b949e;
  --text-muted:#484f58;
  --card-bg:   #161b22;
  --nav-bg:    rgba(13,17,23,0.95);
}

[data-theme="light"], .light-theme {
  --bg:        #f6f8fa;
  --bg2:       #ffffff;
  --bg3:       #f0f2f5;
  --border:    #d0d7de;
  --text:      #24292f;
  --text-dim:  #57606a;
  --text-muted:#8c959f;
  --card-bg:   #ffffff;
  --nav-bg:    rgba(246,248,250,0.95);
}

*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
}

/* ── NAVBAR ─────────────────────────────────────────── */
.navbar {
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 1000;
  padding: 0.6rem 0;
}

.navbar-brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text) !important;
  letter-spacing: -0.02em;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.brand-icon { font-size: 1.3rem; }

.navbar .nav-link {
  color: var(--text-dim) !important;
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem !important;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
}

.navbar .nav-link:hover { color: var(--text) !important; background: var(--bg3); }

.avatar-sm {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px; height: 22px;
  background: var(--blue);
  color: #fff;
  border-radius: 50%;
  font-size: 11px;
  font-weight: 700;
  margin-right: 4px;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-dim);
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.15s;
}
.theme-toggle:hover { background: var(--bg3); }

/* ── BUTTONS ─────────────────────────────────────────── */
.btn-primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
  font-weight: 600;
  font-size: 0.875rem;
}
.btn-primary:hover { background: var(--blue-dim); border-color: var(--blue-dim); color: #fff; }

.btn-outline-primary {
  color: var(--blue);
  border-color: var(--blue);
}
.btn-outline-primary:hover { background: var(--blue); color: #fff; }

.btn-lab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, #1a2a1a, #162016);
  color: var(--green);
  border: 1px solid #2d4a2d;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  transition: all 0.2s;
  margin: 1rem 0;
}
.btn-lab:hover { background: #1f361f; color: var(--green); border-color: #3a6b3a; }

/* ── CARDS ────────────────────────────────────────────── */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.course-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color 0.2s, transform 0.15s, box-shadow 0.2s;
}
.course-card:hover {
  border-color: var(--blue);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(59,130,246,0.15);
  color: inherit;
}

.course-tag {
  display: inline-block;
  background: rgba(59,130,246,0.15);
  color: var(--blue);
  border: 1px solid rgba(59,130,246,0.3);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.course-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.course-desc {
  font-size: 0.875rem;
  color: var(--text-dim);
  line-height: 1.5;
  margin-bottom: 1rem;
}

.course-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── PROGRESS ────────────────────────────────────────── */
.progress {
  height: 6px;
  background: var(--bg3);
  border-radius: 99px;
  overflow: hidden;
}
.progress-bar {
  background: linear-gradient(90deg, var(--blue), #60a5fa);
  border-radius: 99px;
  transition: width 0.6s ease;
}

/* ── LESSON SIDEBAR ──────────────────────────────────── */
.lesson-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  min-height: calc(100vh - 56px);
}

.lesson-sidebar {
  background: var(--bg2);
  border-right: 1px solid var(--border);
  padding: 1.5rem 0;
  overflow-y: auto;
  position: sticky;
  top: 56px;
  height: calc(100vh - 56px);
}

.sidebar-course-title {
  font-weight: 700;
  font-size: 0.875rem;
  padding: 0 1.25rem;
  margin-bottom: 1rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.sidebar-lesson {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0.6rem 1.25rem;
  font-size: 0.875rem;
  color: var(--text-dim);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.15s;
}
.sidebar-lesson:hover { background: var(--bg3); color: var(--text); }
.sidebar-lesson.active {
  background: rgba(59,130,246,0.1);
  color: var(--blue);
  border-left-color: var(--blue);
  font-weight: 600;
}
.sidebar-lesson.done .lesson-check { color: var(--green); }
.sidebar-lesson .lesson-num {
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--bg3);
  font-size: 10px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.sidebar-lesson.active .lesson-num { background: var(--blue); color: #fff; }
.sidebar-lesson.done .lesson-num { background: var(--green); color: #fff; }

/* ── LESSON CONTENT ──────────────────────────────────── */
.lesson-main {
  padding: 2.5rem;
  max-width: 820px;
}

.lesson-content h1 { font-size: 1.75rem; font-weight: 800; letter-spacing: -0.03em; margin-bottom: 0.5rem; }
.lesson-content h2 { font-size: 1.3rem; font-weight: 700; margin-top: 2.5rem; margin-bottom: 0.75rem; }
.lesson-content h3 { font-size: 1.05rem; font-weight: 600; margin-top: 2rem; margin-bottom: 0.5rem; }
.lesson-content p { color: var(--text-dim); margin-bottom: 1rem; }
.lesson-content ul, .lesson-content ol { color: var(--text-dim); padding-left: 1.5rem; margin-bottom: 1rem; }
.lesson-content li { margin-bottom: 0.35rem; }
.lesson-content strong { color: var(--text); }
.lesson-content a { color: var(--blue); }

/* ── CODE BLOCKS ─────────────────────────────────────── */
.code-block-wrapper {
  background: #0d1117;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin: 1.25rem 0;
  overflow: hidden;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 1rem;
  background: #161b22;
  border-bottom: 1px solid var(--border);
}

.code-filename {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-muted);
}

.copy-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s;
}
.copy-btn:hover { color: var(--text); border-color: var(--blue); }
.copy-btn.copied { color: var(--green); border-color: var(--green); }

.code-block {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  padding: 1.25rem;
  margin: 0;
  background: transparent !important;
  overflow-x: auto;
}

/* inline code */
.lesson-content code:not(.code-block code) {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--bg3);
  border: 1px solid var(--border);
  padding: 0.1em 0.4em;
  border-radius: 4px;
  color: var(--amber);
}

/* ── QUIZ ─────────────────────────────────────────────── */
.quiz-container {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 2rem 0;
}

.quiz-question {
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 1rem;
  color: var(--text);
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 0.5rem;
  cursor: pointer;
  transition: all 0.15s;
  font-size: 0.9rem;
  color: var(--text-dim);
}
.quiz-option:hover { border-color: var(--blue); color: var(--text); background: rgba(59,130,246,0.05); }
.quiz-option.selected { border-color: var(--blue); background: rgba(59,130,246,0.1); color: var(--text); }
.quiz-option.correct { border-color: var(--green); background: rgba(16,185,129,0.1); color: var(--green); }
.quiz-option.wrong { border-color: var(--red); background: rgba(239,68,68,0.1); color: var(--red); }

.quiz-explanation {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: var(--bg3);
  border-radius: 8px;
  font-size: 0.875rem;
  color: var(--text-dim);
  display: none;
}
.quiz-explanation.show { display: block; }

/* ── CALLOUTS ─────────────────────────────────────────── */
.callout {
  display: flex;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-radius: 8px;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}
.callout-info { background: rgba(59,130,246,0.1); border-left: 3px solid var(--blue); }
.callout-warning { background: rgba(245,158,11,0.1); border-left: 3px solid var(--amber); }
.callout-tip { background: rgba(16,185,129,0.1); border-left: 3px solid var(--green); }
.callout-danger { background: rgba(239,68,68,0.1); border-left: 3px solid var(--red); }
.callout p { margin: 0; color: var(--text-dim); }

/* ── VIDEO ────────────────────────────────────────────── */
.video-wrapper {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  margin: 1.5rem 0;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.video-wrapper iframe {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
}

/* ── BADGE ────────────────────────────────────────────── */
.badge-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  transition: border-color 0.2s;
}
.badge-card:hover { border-color: var(--amber); }
.badge-icon { font-size: 2.5rem; margin-bottom: 0.5rem; }

/* ── DASHBOARD ───────────────────────────────────────── */
.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
}
.stat-value { font-size: 2rem; font-weight: 800; letter-spacing: -0.04em; }
.stat-label { font-size: 0.8rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.08em; }

/* ── HERO ─────────────────────────────────────────────── */
.hero {
  padding: 5rem 0 3.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -100px; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 600px;
  background: radial-gradient(ellipse, rgba(59,130,246,0.12) 0%, transparent 70%);
  pointer-events: none;
}
.hero-eyebrow {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--blue);
  border: 1px solid rgba(59,130,246,0.3);
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
}
.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: 1.25rem;
}
.hero-title .accent { color: var(--blue); }
.hero-sub {
  font-size: 1.1rem;
  color: var(--text-dim);
  max-width: 480px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

/* ── FORMS ────────────────────────────────────────────── */
.form-control, .form-select {
  background: var(--bg2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 8px;
  padding: 0.6rem 0.875rem;
  font-size: 0.9rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.form-control:focus, .form-select:focus {
  background: var(--bg2);
  border-color: var(--blue);
  color: var(--text);
  box-shadow: 0 0 0 3px rgba(59,130,246,0.2);
}
.form-label { font-size: 0.875rem; font-weight: 600; color: var(--text-dim); margin-bottom: 0.4rem; }

.auth-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 2rem;
  width: 100%;
  max-width: 420px;
  margin: 0 auto;
}

/* ── ALERT ────────────────────────────────────────────── */
.alert { border-radius: 8px; font-size: 0.9rem; }
.alert-success { background: rgba(16,185,129,0.1); border-color: rgba(16,185,129,0.3); color: var(--green); }
.alert-danger  { background: rgba(239,68,68,0.1);  border-color: rgba(239,68,68,0.3);  color: var(--red); }

/* ── ADMIN ────────────────────────────────────────────── */
.admin-sidebar {
  width: 240px;
  background: var(--bg2);
  border-right: 1px solid var(--border);
  min-height: calc(100vh - 56px);
  padding: 1.5rem 0;
  flex-shrink: 0;
}
.admin-nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0.6rem 1.25rem;
  font-size: 0.875rem;
  color: var(--text-dim);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.15s;
}
.admin-nav-link:hover { background: var(--bg3); color: var(--text); }
.admin-nav-link.active { color: var(--blue); border-left-color: var(--blue); background: rgba(59,130,246,0.08); font-weight: 600; }

.table { color: var(--text); }
.table th { color: var(--text-dim); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; border-color: var(--border); }
.table td { border-color: var(--border); font-size: 0.9rem; vertical-align: middle; }
.table tbody tr:hover { background: var(--bg3); }

/* ── FOOTER ───────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.25rem 0;
  margin-top: auto;
}
.footer-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.footer-brand { font-weight: 700; color: var(--text-dim); }
.footer-tagline { margin-left: auto; }

/* ── NEXT/PREV NAV ───────────────────────────────────── */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.lesson-nav a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0.75rem 1.25rem;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.15s;
}
.lesson-nav a:hover { border-color: var(--blue); color: var(--text); }

/* ── UPLOAD ZONE ─────────────────────────────────────── */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 3rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}
.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--blue);
  background: rgba(59,130,246,0.05);
}
.upload-icon { font-size: 2.5rem; margin-bottom: 1rem; }

/* ── RESPONSIVE ──────────────────────────────────────── */
@media (max-width: 768px) {
  .lesson-layout { grid-template-columns: 1fr; }
  .lesson-sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--border); }
  .lesson-main { padding: 1.5rem 1rem; }
  .hero { padding: 3rem 0 2rem; }
  .admin-sidebar { display: none; }
}

/* ── DROPDOWN ────────────────────────────────────────── */
.dropdown-menu {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
  padding: 0.5rem;
}
.dropdown-item { color: var(--text-dim); border-radius: 6px; font-size: 0.875rem; padding: 0.5rem 0.75rem; }
.dropdown-item:hover { background: var(--bg3); color: var(--text); }
.dropdown-divider { border-color: var(--border); }

/* ── COMPLETE BUTTON ─────────────────────────────────── */
.complete-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0.75rem 1.5rem;
  background: var(--green);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: opacity 0.2s;
  margin-top: 2rem;
}
.complete-btn:hover { opacity: 0.85; }
.complete-btn.done { background: var(--bg3); color: var(--text-muted); cursor: default; }