/* ============================================================
   COURSEVAULT — Main Stylesheet
   Dark Cyber-Premium Theme
   Fonts: Syne (display), DM Mono (code/labels), Inter (body)
   ============================================================ */

/* ─── CSS Variables ──────────────────────────────────────────── */
:root {
  --bg-base:       #080c14;
  --bg-surface:    #0d1220;
  --bg-elevated:   #121929;
  --bg-card:       #141c2e;
  --bg-hover:      #1a2340;

  --accent:        #00d4ff;
  --accent-dim:    rgba(0, 212, 255, 0.15);
  --accent-glow:   rgba(0, 212, 255, 0.35);
  --accent-2:      #7b5ea7;
  --accent-3:      #ff6b6b;

  --text-primary:  #eef2ff;
  --text-secondary:#8b9bbf;
  --text-muted:    #4a5878;
  --text-dim:      #2d3a55;

  --border:        rgba(255,255,255,0.07);
  --border-accent: rgba(0,212,255,0.3);

  --font-display:  'Syne', sans-serif;
  --font-mono:     'DM Mono', monospace;
  --font-body:     'Inter', sans-serif;

  --radius-sm:     6px;
  --radius-md:     12px;
  --radius-lg:     18px;
  --radius-xl:     24px;

  --shadow-card:   0 4px 24px rgba(0,0,0,0.4);
  --shadow-glow:   0 0 40px rgba(0,212,255,0.12);
  --transition:    0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1,h2,h3,h4,h5,h6 {
  font-family: var(--font-display);
  color: var(--text-primary);
  line-height: 1.2;
}

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

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

/* ─── Scrollbar ──────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--text-dim); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ─── Utility ────────────────────────────────────────────────── */
.text-accent { color: var(--accent) !important; }
.brand-accent { color: var(--accent); }
.text-muted { color: var(--text-muted) !important; }

/* ─── Navbar ─────────────────────────────────────────────────── */
.site-navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(8,12,20,0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
  transition: background 0.3s;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary) !important;
  letter-spacing: -0.02em;
}

.brand-icon {
  color: var(--accent);
  font-size: 1.4rem;
}

.brand-text { color: var(--text-primary); }

.site-navbar .nav-link {
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.site-navbar .nav-link:hover,
.site-navbar .nav-link.active {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
}

.nav-admin-link {
  font-family: var(--font-mono) !important;
  font-size: 0.8rem !important;
  color: var(--accent) !important;
}

.btn-outline-accent {
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  padding: 5px 14px;
  border-radius: var(--radius-sm);
  background: transparent;
  transition: all var(--transition);
}

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

.navbar-toggler {
  border: 1px solid var(--border);
  padding: 6px 10px;
}

.navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28238,242,255,0.7%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ─── Flash Messages ─────────────────────────────────────────── */
.flash-container {
  position: fixed;
  top: 72px;
  right: 20px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 380px;
  width: 100%;
}

.flash-alert {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid;
  backdrop-filter: blur(20px);
  animation: slideIn 0.3s ease;
  cursor: default;
}

.flash-close {
  background: none;
  border: none;
  color: inherit;
  opacity: 0.6;
  cursor: pointer;
  padding: 0;
  font-size: 1rem;
  line-height: 1;
}
.flash-close:hover { opacity: 1; }

.flash-success {
  background: rgba(16, 185, 129, 0.15);
  border-color: rgba(16, 185, 129, 0.4);
  color: #6ee7b7;
}
.flash-danger {
  background: rgba(239, 68, 68, 0.15);
  border-color: rgba(239, 68, 68, 0.4);
  color: #fca5a5;
}
.flash-warning {
  background: rgba(245, 158, 11, 0.15);
  border-color: rgba(245, 158, 11, 0.4);
  color: #fcd34d;
}
.flash-info {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--border-accent);
  color: var(--accent);
}

@keyframes slideIn {
  from { transform: translateX(110%); opacity: 0; }
  to   { transform: translateX(0);    opacity: 1; }
}

/* ─── Buttons ─────────────────────────────────────────────────── */
.btn-primary-accent {
  background: linear-gradient(135deg, var(--accent), #0099cc);
  color: #000;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 22px;
  transition: all 0.2s ease;
  box-shadow: 0 0 20px rgba(0,212,255,0.2);
}

.btn-primary-accent:hover {
  transform: translateY(-1px);
  box-shadow: 0 0 30px rgba(0,212,255,0.4);
  color: #000;
  background: linear-gradient(135deg, #33ddff, #00aadd);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  font-size: 0.875rem;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.btn-ghost:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.15);
  background: rgba(255,255,255,0.04);
}

.btn-ghost-sm {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  font-size: 0.8rem;
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  cursor: pointer;
}
.btn-ghost-sm:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.2);
}

.btn-view-course {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--border-accent);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.btn-view-course:hover {
  background: var(--accent-dim);
  color: var(--accent);
  box-shadow: 0 0 16px var(--accent-glow);
}

.btn-youtube-external {
  display: inline-flex;
  align-items: center;
  background: rgba(255,0,0,0.12);
  color: #ff4040;
  border: 1px solid rgba(255,0,0,0.3);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  margin-top: 12px;
}
.btn-youtube-external:hover {
  background: rgba(255,0,0,0.2);
  color: #ff6060;
  border-color: rgba(255,0,0,0.5);
}

.btn-xs {
  font-size: 0.75rem;
  padding: 3px 9px;
}

/* ─── Hero Section ───────────────────────────────────────────── */
.hero-section {
  position: relative;
  overflow: hidden;
  padding: 100px 0 80px;
  min-height: 560px;
  display: flex;
  align-items: center;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,212,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,212,255,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black, transparent);
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(0,212,255,0.07) 0%, transparent 65%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 700px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 28px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.badge-dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(1.4); }
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.05;
  margin-bottom: 24px;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.hero-title-accent {
  background: linear-gradient(135deg, var(--accent) 0%, #a78bfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 560px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.hero-stat { text-align: center; }

.stat-value {
  display: block;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
}

.stat-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.hero-stat-divider {
  width: 1px;
  height: 32px;
  background: var(--border);
}

/* ─── Search Section ─────────────────────────────────────────── */
.search-section {
  padding: 32px 0 24px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-surface);
}

.search-bar-form { margin-bottom: 16px; }

.search-input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 6px 6px 6px 20px;
  transition: border-color var(--transition), box-shadow var(--transition);
  max-width: 640px;
}

.search-input-wrap:focus-within {
  border-color: var(--border-accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.search-icon { color: var(--text-muted); margin-right: 12px; font-size: 1rem; }

.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.95rem;
}

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

.search-submit-btn {
  background: var(--accent);
  color: #000;
  border: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.82rem;
  padding: 9px 20px;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition);
}

.search-submit-btn:hover {
  background: #33ddff;
  box-shadow: 0 0 20px rgba(0,212,255,0.3);
}

.quick-filters {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.quick-filter-chip {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 100px;
  transition: all var(--transition);
}

.quick-filter-chip:hover {
  color: var(--accent);
  border-color: var(--border-accent);
  background: var(--accent-dim);
}

/* ─── Section Blocks ─────────────────────────────────────────── */
.section-block {
  padding: 64px 0;
}

.section-header {
  margin-bottom: 40px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

/* ─── Course Card ────────────────────────────────────────────── */
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
  box-shadow: var(--shadow-glow), var(--shadow-card);
}

.course-card-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-elevated);
}

.course-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.course-card:hover .course-card-thumb img {
  transform: scale(1.04);
}

.course-thumb-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: var(--text-dim);
  background: linear-gradient(135deg, #0d1220 0%, #121929 100%);
}

.course-badge-featured {
  position: absolute;
  top: 12px;
  left: 12px;
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: #000;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.course-badge-category {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(10px);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.62rem;
  padding: 3px 9px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border: 1px solid var(--border);
}

.course-card-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.course-card-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.3;
}

.course-card-title a {
  color: var(--text-primary);
}

.course-card-title a:hover { color: var(--accent); }

.course-card-desc {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.5;
  margin-bottom: 12px;
  flex: 1;
}

.course-card-meta {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  background: var(--bg-elevated);
  padding: 3px 9px;
  border-radius: 100px;
  border: 1px solid var(--border);
}

.course-card-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.tag-chip {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--border);
  padding: 2px 9px;
  border-radius: 100px;
  transition: all var(--transition);
  text-transform: lowercase;
}

.tag-chip:hover {
  color: var(--accent);
  border-color: var(--border-accent);
  background: var(--accent-dim);
}

.tag-chip-more {
  color: var(--text-muted);
  cursor: default;
}

.course-card-footer {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

/* ─── Filter Panel ───────────────────────────────────────────── */
.filter-panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  position: sticky;
  top: 90px;
}

.filter-panel-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.filter-group { margin-bottom: 20px; }

.filter-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.filter-search-wrap {
  position: relative;
}

.filter-search-wrap i {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.filter-input {
  width: 100%;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font-size: 0.85rem;
  padding: 8px 12px 8px 32px;
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition);
}

.filter-input:focus {
  border-color: var(--border-accent);
}

.filter-select {
  width: 100%;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font-size: 0.85rem;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
}

.filter-select option { background: var(--bg-elevated); }

.filter-pills {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.filter-pill {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-secondary);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 100px;
  transition: all var(--transition);
  text-transform: capitalize;
}

.filter-pill:hover,
.filter-pill.active {
  color: var(--accent);
  border-color: var(--border-accent);
  background: var(--accent-dim);
}

.filter-pill-sm { font-size: 0.65rem; padding: 3px 8px; }

/* ─── Courses Page Header ────────────────────────────────────── */
.courses-page-header {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  padding: 40px 0 32px;
}

.courses-page-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 6px;
}

.courses-page-sub {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

/* ─── Pagination ─────────────────────────────────────────────── */
.pagination-wrap { display: flex; justify-content: center; }

.custom-pagination .page-link {
  background: var(--bg-card);
  border-color: var(--border);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 8px 14px;
  transition: all var(--transition);
}

.custom-pagination .page-link:hover,
.custom-pagination .page-item.active .page-link {
  background: var(--accent-dim);
  border-color: var(--border-accent);
  color: var(--accent);
}

/* ─── Empty State ────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 72px 24px;
  color: var(--text-muted);
}

.empty-icon {
  font-size: 3.5rem;
  margin-bottom: 16px;
  opacity: 0.3;
}

.empty-state h3 {
  font-size: 1.3rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.empty-state p {
  font-size: 0.9rem;
  margin-bottom: 20px;
}

/* ─── CTA Section ────────────────────────────────────────────── */
.cta-section {
  padding: 80px 0;
  border-top: 1px solid var(--border);
}

.cta-inner {
  position: relative;
  text-align: center;
  padding: 60px 40px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.cta-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(0,212,255,0.07) 0%, transparent 60%);
  pointer-events: none;
}

.cta-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  margin-bottom: 12px;
  position: relative;
}

.cta-sub {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 28px;
  position: relative;
}

/* ─── Footer ─────────────────────────────────────────────────── */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-brand { display: flex; flex-direction: column; gap: 4px; }

.footer-logo {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-tagline {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: color var(--transition);
}

.footer-links a:hover { color: var(--text-primary); }

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ─── Auth Page ──────────────────────────────────────────────── */
.auth-page { background: var(--bg-base); }

.auth-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 16px;
  position: relative;
}

.auth-grid-bg {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,212,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,212,255,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.auth-card {
  position: relative;
  width: 100%;
  max-width: 420px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: 0 24px 80px rgba(0,0,0,0.5);
  animation: fadeUp 0.4s ease;
}

@keyframes fadeUp {
  from { transform: translateY(20px); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

.auth-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 28px;
}

.auth-brand i { color: var(--accent); }

.auth-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.auth-subtitle {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 32px;
}

.auth-form { display: flex; flex-direction: column; gap: 4px; }

.form-group-auth { margin-bottom: 16px; }

.form-label-auth {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.form-control-auth {
  background: var(--bg-elevated) !important;
  border: 1px solid var(--border) !important;
  color: var(--text-primary) !important;
  border-radius: var(--radius-sm) !important;
  padding: 11px 14px !important;
  font-size: 0.95rem;
  transition: border-color var(--transition), box-shadow var(--transition) !important;
  width: 100%;
}

.form-control-auth:focus {
  border-color: var(--border-accent) !important;
  box-shadow: 0 0 0 3px var(--accent-dim) !important;
  outline: none;
}

.form-control-auth::placeholder { color: var(--text-dim) !important; }

.password-input-wrap { position: relative; }

.password-toggle {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0;
  font-size: 0.9rem;
  transition: color var(--transition);
}

.password-toggle:hover { color: var(--text-secondary); }

.form-check-auth {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
}

.form-check-auth .form-check-input {
  background-color: var(--bg-elevated);
  border-color: var(--border);
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.form-check-auth .form-check-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  cursor: pointer;
}

.btn-auth-submit {
  background: linear-gradient(135deg, var(--accent), #0099cc);
  color: #000;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  border: none;
  padding: 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  width: 100%;
  margin-bottom: 20px;
}

.btn-auth-submit:hover {
  box-shadow: 0 0 30px rgba(0,212,255,0.4);
  transform: translateY(-1px);
}

.auth-footer {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.auth-footer a { color: var(--text-secondary); }
.auth-footer a:hover { color: var(--accent); }

/* ─── Bootstrap overrides ────────────────────────────────────── */
.form-control, .form-select {
  background-color: var(--bg-elevated);
  border-color: var(--border);
  color: var(--text-primary);
}

.form-control:focus, .form-select:focus {
  background-color: var(--bg-elevated);
  border-color: var(--border-accent);
  color: var(--text-primary);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.form-control::placeholder { color: var(--text-dim); }
.form-select option { background: var(--bg-elevated); }

.btn-secondary {
  background: var(--bg-elevated);
  border-color: var(--border);
  color: var(--text-secondary);
}

.btn-secondary:hover {
  background: var(--bg-hover);
  border-color: rgba(255,255,255,0.15);
  color: var(--text-primary);
}

.btn-outline-danger {
  border-color: rgba(239,68,68,0.4);
  color: #ef4444;
  background: transparent;
}

.btn-outline-danger:hover {
  background: rgba(239,68,68,0.12);
  border-color: rgba(239,68,68,0.6);
  color: #ef4444;
}

.btn-outline-secondary {
  border-color: var(--border);
  color: var(--text-secondary);
  background: transparent;
}

.btn-outline-secondary:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.15);
}

.invalid-feedback { color: #fca5a5 !important; font-size: 0.8rem; }
.is-invalid { border-color: rgba(239,68,68,0.6) !important; }

/* ─── Responsive ─────────────────────────────────────────────── */
@media (max-width: 991px) {
  .hero-section { padding: 60px 0 50px; }
  .hero-title { font-size: 2.2rem; }
  .hero-actions { flex-direction: column; align-items: flex-start; }
  .footer-inner { flex-direction: column; align-items: flex-start; gap: 16px; }
}

@media (max-width: 767px) {
  .hero-section { padding: 50px 0 40px; min-height: unset; }
  .hero-title { font-size: 1.9rem; }
  .hero-subtitle { font-size: 0.95rem; }
  .section-block { padding: 40px 0; }
  .auth-card { padding: 28px 20px; }
  .flash-container { right: 10px; left: 10px; max-width: none; }
  .search-submit-btn span { display: none; }
  .filter-panel { position: static; }
}

/* ─── HackSecGo Logo ─────────────────────────────────────────── */
.brand-logo-img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  border-radius: 6px;
  flex-shrink: 0;
}

.sidebar-logo {
  width: 28px;
  height: 28px;
}

.auth-logo {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.footer-logo-img {
  width: 20px;
  height: 20px;
  object-fit: contain;
  border-radius: 4px;
  vertical-align: middle;
  margin-right: 2px;
}

/* ─── About Page ─────────────────────────────────────────────── */
.about-hero {
  padding: 60px 0 40px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-surface);
}
.about-hero-inner { max-width: 640px; }
.about-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}
.about-lead {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.65;
}
.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 24px;
  position: relative;
  overflow: hidden;
}
.about-card h2 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
}
.about-card p { color: var(--text-secondary); line-height: 1.75; margin-bottom: 12px; }
.about-card-icon {
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: 16px;
}
.about-features-grid { display: flex; flex-direction: column; gap: 20px; }
.about-feature {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}
.about-feature > i {
  font-size: 1.4rem;
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 2px;
}
.about-feature h4 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 4px;
}
.about-feature p { font-size: 0.875rem; color: var(--text-secondary); margin: 0; }
.about-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.about-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.about-list li i { color: var(--accent); flex-shrink: 0; }
.about-card-cta { text-align: center; border-color: var(--border-accent); }
.about-cta-glow {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 400px; height: 300px;
  background: radial-gradient(circle, rgba(0,212,255,0.06) 0%, transparent 65%);
  pointer-events: none;
}

/* ─── Lab Cards ──────────────────────────────────────────────── */
.lab-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  height: 100%;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.lab-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
  box-shadow: var(--shadow-glow);
}
.lab-card-header {
  display: flex;
  gap: 8px;
  padding: 14px 16px 0;
  flex-wrap: wrap;
}
.lab-difficulty {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 3px 9px;
  border-radius: 100px;
}
.lab-diff-beginner    { background: rgba(16,185,129,0.12); color: #34d399; border: 1px solid rgba(16,185,129,0.25); }
.lab-diff-intermediate{ background: rgba(245,158,11,0.12); color: #fbbf24; border: 1px solid rgba(245,158,11,0.25); }
.lab-diff-advanced    { background: rgba(239,68,68,0.12);  color: #f87171; border: 1px solid rgba(239,68,68,0.25); }
.lab-category {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-muted);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 3px 9px;
  border-radius: 100px;
}
.lab-card-body { padding: 16px; flex: 1; }
.lab-icon { font-size: 1.6rem; color: var(--accent); margin-bottom: 10px; opacity: 0.7; }
.lab-card-title { font-family: var(--font-display); font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.lab-card-title a { color: var(--text-primary); }
.lab-card-title a:hover { color: var(--accent); }
.lab-card-desc { font-size: 0.83rem; color: var(--text-secondary); line-height: 1.5; margin-bottom: 10px; }
.lab-tags { display: flex; gap: 5px; flex-wrap: wrap; }
.lab-card-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.btn-lab-download {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-accent);
  color: var(--accent);
  background: var(--accent-dim);
  transition: all var(--transition);
  font-size: 0.9rem;
  text-decoration: none;
  flex-shrink: 0;
}
.btn-lab-download:hover { background: rgba(0,212,255,0.25); color: var(--accent); }

/* ─── Tool Cards ─────────────────────────────────────────────── */
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  height: 100%;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.tool-card:hover {
  transform: translateY(-4px);
  border-color: rgba(123,94,167,0.4);
  box-shadow: 0 0 40px rgba(123,94,167,0.1);
}
.tool-card-header {
  display: flex;
  gap: 8px;
  padding: 14px 16px 0;
  flex-wrap: wrap;
}
.tool-lang-badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #a78bfa;
  background: rgba(123,94,167,0.12);
  border: 1px solid rgba(123,94,167,0.25);
  padding: 3px 9px;
  border-radius: 100px;
}
.tool-card-body { padding: 16px; flex: 1; }
.tool-icon { font-size: 1.6rem; color: #a78bfa; margin-bottom: 10px; opacity: 0.7; }
.tool-card-title { font-family: var(--font-display); font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.tool-card-title a { color: var(--text-primary); }
.tool-card-title a:hover { color: #a78bfa; }
.tool-card-desc { font-size: 0.83rem; color: var(--text-secondary); line-height: 1.5; margin-bottom: 10px; }
.tool-tags { display: flex; gap: 5px; flex-wrap: wrap; }
.tool-card-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.btn-github-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(123,94,167,0.3);
  color: #a78bfa;
  background: rgba(123,94,167,0.08);
  transition: all var(--transition);
  font-size: 1rem;
  text-decoration: none;
  flex-shrink: 0;
}
.btn-github-link:hover { background: rgba(123,94,167,0.2); color: #a78bfa; }

/* ─── Lab Instructions monospace ────────────────────────────── */
.lab-instructions {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.8;
  white-space: pre-wrap;
  font-family: var(--font-mono);
}

.font-mono { font-family: var(--font-mono) !important; font-size: 0.85rem !important; }