/* ============================================================
   StudyCode — Production CSS
   Font: Outfit (display) + DM Sans (body) via Google Fonts
   Theme: Dark-first nav, clean white content, sharp accents
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@400;500;600;700&family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;1,9..40,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- CSS Variables (Light Mode) ---------- */

:root {
  --font-display: 'Outfit', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --color-bg:         #f7f8fc;
  --color-surface:    #ffffff;
  --color-surface-2:  #f0f2f8;
  --color-border:     #e4e7f0;
  --color-border-2:   #d0d5e8;

  --color-text:       #0f1117;
  --color-text-2:     #4a5068;
  --color-text-3:     #8b93b0;

  --color-accent:     #3b6ff0;
  --color-accent-2:   #2554d8;
  --color-accent-bg:  #eff3fe;

  --color-green:      #16a34a;
  --color-green-bg:   #dcfce7;
  --color-amber:      #d97706;
  --color-amber-bg:   #fef3c7;
  --color-red:        #dc2626;
  --color-red-bg:     #fee2e2;

  --nav-bg:           #0d1117;
  --nav-text:         #e2e8f0;
  --nav-text-muted:   #8b96b0;
  --nav-accent:       #60a5fa;
  --nav-border:       rgba(255,255,255,0.07);

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  16px;
  --radius-xl:  24px;

  --shadow-sm:  0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:  0 4px 12px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg:  0 10px 30px rgba(0,0,0,0.10), 0 4px 8px rgba(0,0,0,0.05);

  --transition: 0.2s ease;
}

/* ---------- CSS Variables (Dark Mode) ---------- */

body.dark-mode {
  --color-bg:         #0b0e17;
  --color-surface:    #141824;
  --color-surface-2:  #1c2133;
  --color-border:     #252d42;
  --color-border-2:   #2e3852;

  --color-text:       #edf0f8;
  --color-text-2:     #8b96b8;
  --color-text-3:     #505878;

  --color-accent:     #60a5fa;
  --color-accent-2:   #93c5fd;
  --color-accent-bg:  #1a2640;

  --color-green:      #4ade80;
  --color-green-bg:   #052e16;
  --color-amber:      #fbbf24;
  --color-amber-bg:   #1c1500;
  --color-red:        #f87171;
  --color-red-bg:     #1f0606;

  --shadow-sm:  0 1px 3px rgba(0,0,0,0.3);
  --shadow-md:  0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg:  0 10px 30px rgba(0,0,0,0.5);
}

/* ---------- Reset & Base ---------- */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-2);
}

/* ---------- Navbar ---------- */

.navbar {
  background: var(--nav-bg);
  border-bottom: 1px solid var(--nav-border);
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 1px 20px rgba(0,0,0,0.3);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

/* Logo */
.logo a {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  text-decoration: none;
  letter-spacing: -0.3px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo a::before {
  content: '⟨/⟩';
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--nav-accent);
  background: rgba(96,165,250,0.12);
  padding: 3px 7px;
  border-radius: var(--radius-sm);
}

/* Nav Links */
.nav-links {
  display: flex;
  list-style: none;
  gap: 4px;
  align-items: center;
}

.nav-links li a {
  color: var(--nav-text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  display: block;
}

.nav-links li a:hover {
  color: var(--nav-text);
  background: rgba(255,255,255,0.06);
}

.nav-links li a.active {
  color: var(--nav-accent);
  background: rgba(96,165,250,0.10);
}

/* Nav Actions */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Theme Toggle */
.theme-toggle {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.10);
  color: var(--nav-text-muted);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  background: rgba(255,255,255,0.10);
  color: #fff;
}

/* Navbar Buttons (Sign up = solid, Log in = outline) */
/* Navbar Buttons */
.login {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  font-family: var(--font-display);
  font-weight: 600;
  font-size: 13px;

  padding: 7px 16px;
  border-radius: var(--radius-sm);

  text-decoration: none;
  white-space: nowrap;

  background: var(--nav-accent);
  color: #ffffff !important;

  border: 1px solid transparent;
  transition: all var(--transition);
}

.login:hover {
  background: #93c5fd;
  color: #ffffff !important;
}

/* Outline version */
.login.btn-outline-nav {
  background: transparent;
  color: #e2e8f0 !important;
  border: 1px solid rgba(255,255,255,0.35);
}

.login.btn-outline-nav:hover {
  background: rgba(255,255,255,0.10);
  color: #ffffff !important;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--nav-text);
  font-size: 22px;
  cursor: pointer;
  padding: 4px;
  line-height: 1;
}

/* ---------- Hero Section ---------- */

.hero {
  background: var(--nav-bg);
  border-bottom: 1px solid var(--nav-border);
  padding: 72px 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -60px; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 300px;
  background: radial-gradient(ellipse, rgba(96,165,250,0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(96,165,250,0.12);
  border: 1px solid rgba(96,165,250,0.25);
  color: var(--nav-accent);
  font-size: 12px;
  font-weight: 600;
  font-family: var(--font-display);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 100px;
  margin-bottom: 20px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 54px);
  font-weight: 700;
  color: #ffffff;
  line-height: 1.15;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.hero h1 span {
  color: var(--nav-accent);
}

.hero p {
  font-size: 17px;
  color: var(--nav-text-muted);
  max-width: 500px;
  margin: 0 auto 32px;
  line-height: 1.7;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--nav-accent);
  color: #0d1117;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  transition: all var(--transition);
  box-shadow: 0 4px 20px rgba(96,165,250,0.3);
}

.hero-cta:hover {
  background: #93c5fd;
  color: #0d1117;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(96,165,250,0.4);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 48px;
  padding-top: 40px;
  border-top: 1px solid var(--nav-border);
}

.hero-stat-num {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
  color: #fff;
  display: block;
}

.hero-stat-label {
  font-size: 13px;
  color: var(--nav-text-muted);
}

/* ---------- Section Headers ---------- */

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
}

.section-title {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.3px;
}

.section-title::before {
  content: '';
  display: inline-block;
  width: 3px;
  height: 20px;
  background: var(--color-accent);
  border-radius: 2px;
  margin-right: 10px;
  vertical-align: middle;
}

/* ---------- Tutorial Cards ---------- */

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #818cf8);
  opacity: 0;
  transition: opacity var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-2);
}

.card:hover::before {
  opacity: 1;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

.badge {
  display: inline-flex;
  align-items: center;
  font-size: 11px;
  font-weight: 600;
  font-family: var(--font-display);
  padding: 3px 9px;
  border-radius: 100px;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.badge-beginner {
  background: var(--color-green-bg);
  color: var(--color-green);
}

.badge-intermediate {
  background: var(--color-amber-bg);
  color: var(--color-amber);
}

.badge-advanced {
  background: var(--color-red-bg);
  color: var(--color-red);
}

.badge-guide {
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

.card-read-time {
  font-size: 12px;
  color: var(--color-text-3);
  margin-left: auto;
}

.card h5 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
  line-height: 1.35;
}

.card p {
  font-size: 14px;
  color: var(--color-text-2);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 20px;
}

.btn-card {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-accent-bg);
  color: var(--color-accent);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 13px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  align-self: flex-start;
  border: 1px solid transparent;
}

.btn-card:hover {
  background: var(--color-accent);
  color: #fff;
  gap: 10px;
}

/* ---------- Sidebar (Tutorial Page) ---------- */

.sidebar-wrapper {
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  height: calc(100vh - 60px);
  position: sticky;
  top: 60px;
  overflow-y: auto;
  padding: 20px 0;
}

.sidebar-wrapper::-webkit-scrollbar {
  width: 4px;
}

.sidebar-wrapper::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar-wrapper::-webkit-scrollbar-thumb {
  background: var(--color-border-2);
  border-radius: 2px;
}

.sidebar-title {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--color-text-3);
  padding: 0 16px;
  margin-bottom: 12px;
}

/* Search box */
.sidebar-search {
  margin: 0 12px 16px;
  position: relative;
}

.sidebar-search input {
  width: 100%;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px 12px 8px 32px;
  font-size: 13px;
  font-family: var(--font-body);
  color: var(--color-text);
  transition: all var(--transition);
  outline: none;
}

.sidebar-search input:focus {
  border-color: var(--color-accent);
  background: var(--color-surface);
  box-shadow: 0 0 0 3px rgba(59,111,240,0.12);
}

.sidebar-search input::placeholder {
  color: var(--color-text-3);
}

.sidebar-search::before {
  content: '⌕';
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-3);
  font-size: 16px;
  pointer-events: none;
}

/* Sidebar nav links */
.sidebar-nav {
  list-style: none;
  padding: 0 8px;
}

.sidebar-nav .nav-item a {
  display: block;
  padding: 8px 12px;
  font-size: 13.5px;
  color: var(--color-text-2);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  line-height: 1.4;
}

.sidebar-nav .nav-item a:hover {
  background: var(--color-surface-2);
  color: var(--color-text);
  padding-left: 16px;
}

.sidebar-nav .nav-item a.active {
  background: var(--color-accent-bg);
  color: var(--color-accent);
  font-weight: 500;
}

/* ---------- Tutorial Content ---------- */

.tutorial-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px 44px;
  box-shadow: var(--shadow-sm);
}

.tutorial-content h1,
.tutorial-content h2,
.tutorial-content h3,
.tutorial-content h4 {
  font-family: var(--font-display);
  color: var(--color-text);
  letter-spacing: -0.2px;
  margin-top: 2em;
  margin-bottom: 0.6em;
  line-height: 1.3;
}

.tutorial-content h1 { font-size: 30px; font-weight: 700; margin-top: 0; }
.tutorial-content h2 { font-size: 22px; font-weight: 700; padding-bottom: 8px; border-bottom: 1px solid var(--color-border); }
.tutorial-content h3 { font-size: 18px; font-weight: 600; }
.tutorial-content h4 { font-size: 15px; font-weight: 600; }

.tutorial-content p {
  color: var(--color-text-2);
  margin-bottom: 1em;
  font-size: 15.5px;
}

.tutorial-content ul,
.tutorial-content ol {
  color: var(--color-text-2);
  padding-left: 1.5em;
  margin-bottom: 1em;
  font-size: 15.5px;
}

.tutorial-content li {
  margin-bottom: 4px;
}

.tutorial-content strong {
  color: var(--color-text);
  font-weight: 600;
}

.tutorial-content blockquote {
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-bg);
  margin: 1.5em 0;
  padding: 14px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-text-2);
  font-size: 14.5px;
}

/* ---------- Code Blocks ---------- */

pre {
  position: relative;
  background: #0d1117;
  color: #e6edf3;
  padding: 20px 20px 20px 20px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 1.5em 0;
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.7;
  border: 1px solid #21262d;
  box-shadow: var(--shadow-sm);
}

pre code {
  background: none !important;
  color: inherit;
  padding: 0;
  font-size: inherit;
  border-radius: 0;
}

/* Inline code */
:not(pre) > code {
  background: var(--color-surface-2);
  color: var(--color-accent);
  padding: 2px 7px;
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 13px;
  border: 1px solid var(--color-border);
}

/* Copy button */
.copy-btn {
  position: absolute;
  right: 10px;
  top: 10px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.10);
  color: #8b96b0;
  padding: 5px 9px;
  font-size: 13px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-body);
}

.copy-btn:hover {
  background: rgba(255,255,255,0.12);
  color: #fff;
}

.copy-btn i {
  pointer-events: none;
}

/* ---------- Tables ---------- */

.tutorial-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 14px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.tutorial-content th {
  background: var(--color-surface-2);
  color: var(--color-text);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  padding: 11px 14px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.tutorial-content td {
  padding: 10px 14px;
  color: var(--color-text-2);
  border-bottom: 1px solid var(--color-border);
}

.tutorial-content tr:last-child td {
  border-bottom: none;
}

.tutorial-content tr:hover td {
  background: var(--color-surface-2);
}

/* ---------- TOC ---------- */

.toc-wrapper {
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding: 0 4px;
}

.toc-wrapper::-webkit-scrollbar { width: 3px; }
.toc-wrapper::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 2px; }

.toc-label {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--color-text-3);
  margin-bottom: 10px;
  display: block;
}

.toc ul {
  list-style: none;
  padding-left: 0;
  font-size: 13px;
}

.toc li {
  margin-bottom: 4px;
}

.toc a {
  color: var(--color-text-3);
  text-decoration: none;
  display: block;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: all var(--transition);
  line-height: 1.4;
}

.toc a:hover {
  color: var(--color-accent);
  background: var(--color-accent-bg);
  border-left-color: var(--color-accent);
}

/* ---------- Progress Bar ---------- */

#progressBar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #818cf8);
  width: 0%;
  z-index: 9999;
  transition: width 0.1s linear;
  box-shadow: 0 0 8px rgba(59,111,240,0.5);
}

/* ---------- Nav Buttons (prev/next) ---------- */

.tutorial-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  transition: all var(--transition);
  border: 1px solid var(--color-border);
  color: var(--color-text-2);
  background: var(--color-surface);
  max-width: 220px;
}

.tutorial-nav-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-bg);
}

.tutorial-nav-btn small {
  display: block;
  font-size: 11px;
  font-weight: 400;
  color: var(--color-text-3);
  font-family: var(--font-body);
  margin-bottom: 2px;
}

/* ---------- Dashboard ---------- */

.dashboard-stat {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  transition: all var(--transition);
}

.dashboard-stat:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.dashboard-stat-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--color-accent-bg);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}

.dashboard-stat-num {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1;
  margin-bottom: 4px;
}

.dashboard-stat-label {
  font-size: 13px;
  color: var(--color-text-3);
  font-weight: 500;
}

/* ---------- About Page ---------- */

.about-feature {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  transition: all var(--transition);
}

.about-feature:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-sm);
}

.about-feature-icon {
  font-size: 24px;
  width: 44px;
  text-align: center;
  flex-shrink: 0;
}

/* ---------- 404 Page ---------- */

.error-page {
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 24px;
}

.error-code {
  font-family: var(--font-display);
  font-size: clamp(80px, 15vw, 140px);
  font-weight: 700;
  color: var(--color-border-2);
  line-height: 1;
  margin-bottom: 8px;
}

.error-title {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 12px;
}

.error-subtitle {
  color: var(--color-text-3);
  font-size: 15px;
  margin-bottom: 32px;
}

/* ---------- General Buttons ---------- */

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}

.btn-primary:hover {
  background: var(--color-accent-2);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(59,111,240,0.35);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  color: var(--color-text-2);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-bg);
}

/* ---------- Footer ---------- */

footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
  text-align: center;
  color: var(--color-text-3);
  font-size: 13px;
  margin-top: 80px;
}

footer a {
  color: var(--color-text-3);
  transition: color var(--transition);
}

footer a:hover {
  color: var(--color-accent);
}

/* ---------- Utility ---------- */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.mt-section {
  margin-top: 60px;
}

.text-muted {
  color: var(--color-text-3) !important;
}

/* ---------- Responsive ---------- */

@media (max-width: 992px) {
  .tutorial-content {
    padding: 28px 24px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    background: #0d1117;
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 16px 16px;
    border-bottom: 1px solid var(--nav-border);
    display: none;
    gap: 2px;
  }

  .nav-links.show {
    display: flex;
  }

  .nav-links li a {
    font-size: 15px;
    padding: 10px 12px;
  }

  .menu-toggle {
    display: block;
  }



  .hero {
    padding: 48px 20px 56px;
  }

  .hero-stats {
    gap: 24px;
  }

  .tutorial-content {
    padding: 20px 16px;
  }

  .sidebar-wrapper {
    display: none;
  }

  .sidebar-wrapper.show {
    display: block;
    position: fixed;
    top: 60px;
    left: 0;
    width: 280px;
    height: calc(100vh - 60px);
    z-index: 999;
    box-shadow: var(--shadow-lg);
  }
}

/* ---------- Scroll animations ---------- */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

.fade-up {
  animation: fadeUp 0.4s ease forwards;
}

.fade-up-delay-1 { animation-delay: 0.05s; opacity: 0; }
.fade-up-delay-2 { animation-delay: 0.10s; opacity: 0; }
.fade-up-delay-3 { animation-delay: 0.15s; opacity: 0; }
.fade-up-delay-4 { animation-delay: 0.20s; opacity: 0; }

/* ---------- Progress bar scroll script target ---------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* btn-outline-nav rules defined above */

/* ---------- Auth Pages ---------- */

.auth-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-md);
}

.auth-field {
  margin-bottom: 18px;
}

.auth-label {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.auth-input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 14px;
  transition: all var(--transition);
  outline: none;
}

.auth-input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(59,111,240,0.12);
}

.auth-input::placeholder {
  color: var(--color-text-3);
}

.auth-flash {
  padding: 12px 14px;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  font-size: 14px;
}

.auth-flash-success {
  background: var(--color-green-bg);
  color: var(--color-green);
}

.auth-flash-error {
  background: var(--color-red-bg);
  color: var(--color-red);
}

.tutorial-row-border {
    border-bottom: 1px solid var(--color-border);
}