/* ================================================================
   assets/css/main.css
   Platform Pembelajaran — Modern Glassmorphism Design
   ================================================================ */

/* ── 1. CSS Variables ──────────────────────────────────────────── */
:root {
  /* Warna Utama */
  --color-bg:        #FFFFFF;
  --color-accent:    #2563EB;
  --color-accent-h:  #1D4ED8;   /* hover */
  --color-accent-l:  #EFF6FF;   /* light tint */
  --color-text:      #111827;
  --color-text-muted:#6B7280;
  --color-border:    rgba(37,99,235,0.15);

  /* Glass */
  --glass-bg:        rgba(255,255,255,0.72);
  --glass-border:    rgba(255,255,255,0.5);
  --glass-blur:      blur(18px);
  --glass-shadow:    0 8px 32px rgba(37,99,235,0.10);

  /* Spacing */
  --nav-h: 68px;
  --radius: 16px;
  --radius-sm: 10px;

  /* Tipografi */
  --font-display: 'Plus Jakarta Sans', 'Nunito', sans-serif;
  --font-body:    'Inter', system-ui, sans-serif;

  /* Transition */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur:  0.28s;
}

/* ── 2. Reset & Base ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Background dekoratif */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% -10%, rgba(37,99,235,0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 110%, rgba(37,99,235,0.06) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* ── 3. Typography ─────────────────────────────────────────────── */
h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
}

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

img { max-width: 100%; display: block; }

/* ── 4. Navbar ─────────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  padding: 0 max(1.25rem, env(safe-area-inset-left));
  background: rgba(255,255,255,0.80);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  transition: box-shadow var(--dur) var(--ease);
}

.navbar.scrolled {
  box-shadow: 0 4px 24px rgba(37,99,235,0.14);
}

.nav-inner {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

/* Logo */
.nav-logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  flex-shrink: 0;
}
.nav-logo span.logo-dot {
  display: inline-block;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
}

/* Menu links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}
.nav-links a {
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: all var(--dur) var(--ease);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
  background: var(--color-accent-l);
}

/* Nav actions */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

/* Avatar + Dropdown */
.nav-user {
  position: relative;
}
.avatar-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  padding: 0.3rem 0.6rem 0.3rem 0.3rem;
  border-radius: 40px;
  background: var(--color-accent-l);
  border: 1.5px solid var(--color-border);
  transition: all var(--dur) var(--ease);
}
.avatar-btn:hover { background: #dbeafe; border-color: var(--color-accent); }

.avatar-circle {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.8rem;
  display: flex; align-items: center; justify-content: center;
  letter-spacing: 0.03em;
}
.avatar-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-text);
  max-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.avatar-chevron {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  transition: transform var(--dur) var(--ease);
}
.nav-user.open .avatar-chevron { transform: rotate(180deg); }

.dropdown {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 180px;
  background: rgba(255,255,255,0.95);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: 0 20px 60px rgba(37,99,235,0.16);
  padding: 0.5rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px) scale(0.97);
  transition: all var(--dur) var(--ease);
  z-index: 200;
}
.nav-user.open .dropdown {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0) scale(1);
}
.dropdown a, .dropdown button {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  width: 100%;
  padding: 0.55rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  background: none;
  border: none;
  cursor: pointer;
  transition: background var(--dur) var(--ease);
}
.dropdown a:hover, .dropdown button:hover { background: var(--color-accent-l); }
.dropdown .divider {
  height: 1px;
  background: var(--color-border);
  margin: 0.3rem 0;
}
.dropdown .logout-btn { color: #DC2626; }
.dropdown .logout-btn:hover { background: #FEF2F2; }

/* Hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 0.4rem;
  border-radius: var(--radius-sm);
  background: none;
  border: none;
}
.nav-hamburger span {
  display: block;
  width: 22px; height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--dur) var(--ease);
}

/* ── 5. Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  border: none;
  outline: none;
  text-decoration: none;
  transition: all var(--dur) var(--ease);
  position: relative;
  overflow: hidden;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 2px 12px rgba(37,99,235,0.25);
}
.btn-primary:hover {
  background: var(--color-accent-h);
  box-shadow: 0 6px 24px rgba(37,99,235,0.40);
  transform: translateY(-1px);
  color: #fff;
  text-decoration: none;
}

.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}
.btn-outline:hover {
  background: var(--color-accent-l);
  box-shadow: 0 4px 16px rgba(37,99,235,0.20);
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}
.btn-ghost:hover {
  background: var(--color-accent-l);
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.btn-lg { padding: 0.85rem 1.75rem; font-size: 1rem; border-radius: 12px; }
.btn-sm { padding: 0.4rem 0.9rem; font-size: 0.82rem; }

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  pointer-events: none;
}

/* ── 6. Sections ───────────────────────────────────────────────── */
section {
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── 7. Hero Section ───────────────────────────────────────────── */
#beranda {
  display: flex;
  align-items: center;
  padding-top: var(--nav-h);
  min-height: 100vh;
  overflow: hidden;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
  padding: 4rem 0 3rem;
  width: 100%;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  background: var(--color-accent-l);
  border: 1px solid rgba(37,99,235,0.25);
  border-radius: 40px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  color: var(--color-text);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.hero-title .highlight {
  color: var(--color-accent);
  position: relative;
}
.hero-title .highlight::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #60A5FA);
  border-radius: 2px;
  opacity: 0.4;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.hero-stats {
  display: flex;
  gap: 2rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
  flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-num {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--color-accent);
}
.stat-label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-weight: 500;
  margin-top: 0.1rem;
}

/* Hero visual / illustration */
.hero-visual {
  display: none; /* tampil di desktop */
  position: relative;
}
.hero-card-stack {
  position: relative;
  width: 360px;
  height: 320px;
  margin: 0 auto;
}
.hcard {
  position: absolute;
  border-radius: var(--radius);
  padding: 1.2rem 1.5rem;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}
.hcard-main {
  top: 0; left: 0;
  width: 240px;
  animation: floatY 4s ease-in-out infinite;
}
.hcard-side {
  bottom: 0; right: 0;
  width: 200px;
  animation: floatY 4s ease-in-out infinite 1.5s;
}
@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-12px); }
}

/* ── 8. Keunggulan ─────────────────────────────────────────────── */
.features-section {
  padding: 3rem 0 4rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.feature-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  padding: 1.5rem;
  transition: all var(--dur) var(--ease);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(37,99,235,0.14);
  border-color: rgba(37,99,235,0.25);
}
.feature-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: var(--color-accent-l);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1rem;
}
.feature-card h3 {
  font-size: 1rem;
  margin-bottom: 0.4rem;
}
.feature-card p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* Section header */
.section-header {
  text-align: center;
  margin-bottom: 0.5rem;
}
.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}
.section-title {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  color: var(--color-text);
  margin-bottom: 0.75rem;
}
.section-desc {
  font-size: 1rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ── 9. Mata Pelajaran Section ─────────────────────────────────── */
#mapel {
  padding-top: calc(var(--nav-h) + 3rem);
  padding-bottom: 5rem;
}

.mapel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.mapel-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: all 0.3s var(--ease);
  position: relative;
  overflow: hidden;
}
.mapel-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #60A5FA);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease);
}
.mapel-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 64px rgba(37,99,235,0.15);
  border-color: rgba(37,99,235,0.30);
}
.mapel-card:hover::before { transform: scaleX(1); }

.mapel-icon-wrap {
  width: 60px; height: 60px;
  border-radius: 16px;
  background: var(--color-accent-l);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.8rem;
  border: 1.5px solid rgba(37,99,235,0.15);
}
.mapel-card-body { flex: 1; }
.mapel-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}
.mapel-card-desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}
.mapel-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.78rem;
  color: var(--color-text-muted);
}
.mapel-tag {
  background: var(--color-accent-l);
  color: var(--color-accent);
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  font-weight: 600;
}
.mapel-card-footer {
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

/* ── 10. Kontak Section ────────────────────────────────────────── */
#kontak {
  padding-top: calc(var(--nav-h) + 3rem);
  padding-bottom: 6rem;
}

.kontak-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 2.5rem;
}

.kontak-info h3 {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
}
.kontak-info p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 1.5rem;
}
.kontak-item {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  margin-bottom: 1rem;
  font-size: 0.9rem;
}
.kontak-item-icon {
  font-size: 1.2rem;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

/* Form */
.form-glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  padding: 2rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
}
.form-group .required { color: #DC2626; margin-left: 2px; }

.form-control {
  width: 100%;
  padding: 0.65rem 0.9rem;
  border: 1.5px solid rgba(209,213,219,0.8);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-family: var(--font-body);
  color: var(--color-text);
  background: rgba(255,255,255,0.8);
  transition: all var(--dur) var(--ease);
  outline: none;
  resize: vertical;
}
.form-control:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
  background: #fff;
}
.form-control.error {
  border-color: #DC2626;
  box-shadow: 0 0 0 3px rgba(220,38,38,0.10);
}

.field-error {
  font-size: 0.78rem;
  color: #DC2626;
  margin-top: 0.2rem;
  display: none;
}
.field-error.show { display: block; }

textarea.form-control { min-height: 130px; }

/* Alert toast */
.alert {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 1rem;
  opacity: 0;
  transform: translateY(-6px);
  transition: all var(--dur) var(--ease);
  pointer-events: none;
}
.alert.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}
.alert-success {
  background: #F0FDF4;
  border: 1px solid #BBF7D0;
  color: #15803D;
}
.alert-error {
  background: #FFF1F2;
  border: 1px solid #FECDD3;
  color: #BE123C;
}

/* ── 11. Modal Auth ─────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(17,24,39,0.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur) var(--ease);
}
.modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.modal {
  background: rgba(255,255,255,0.96);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  box-shadow: 0 30px 80px rgba(17,24,39,0.20);
  padding: 2rem;
  width: 100%;
  max-width: 420px;
  transform: translateY(16px) scale(0.98);
  transition: transform var(--dur) var(--ease);
  position: relative;
}
.modal-overlay.open .modal {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 1rem; right: 1rem;
  width: 32px; height: 32px;
  border-radius: 50%;
  background: var(--color-accent-l);
  border: none;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  color: var(--color-text-muted);
  transition: all var(--dur) var(--ease);
}
.modal-close:hover { background: #dbeafe; color: var(--color-text); }

.modal-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.modal-logo-icon {
  width: 40px; height: 40px;
  background: var(--color-accent);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: #fff;
  font-size: 1.2rem;
}

.modal h2 { font-size: 1.4rem; margin-bottom: 0.3rem; }
.modal p.modal-sub { font-size: 0.875rem; color: var(--color-text-muted); margin-bottom: 1.5rem; }

.modal-tabs {
  display: flex;
  background: var(--color-accent-l);
  border-radius: var(--radius-sm);
  padding: 0.3rem;
  margin-bottom: 1.5rem;
  gap: 0.25rem;
}
.modal-tab {
  flex: 1;
  padding: 0.5rem;
  border-radius: 8px;
  border: none;
  background: transparent;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--dur) var(--ease);
}
.modal-tab.active {
  background: #fff;
  color: var(--color-accent);
  box-shadow: 0 2px 8px rgba(37,99,235,0.12);
}

.tab-pane { display: none; }
.tab-pane.active { display: block; }

.modal-footer-text {
  text-align: center;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-top: 1rem;
}
.modal-footer-text a {
  color: var(--color-accent);
  font-weight: 600;
}

/* ── 12. Profile Modal ──────────────────────────────────────────── */
#profile-modal .modal { max-width: 460px; }

.profile-avatar-lg {
  width: 72px; height: 72px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 0.75rem;
  letter-spacing: 0.03em;
}

/* ── 13. Footer ─────────────────────────────────────────────────── */
footer {
  background: var(--color-text);
  color: rgba(255,255,255,0.65);
  padding: 1.5rem 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  position: relative;
  z-index: 1;
}
footer .footer-logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  color: #fff;
  margin-bottom: 0.5rem;
}
footer .footer-copy {
  color: rgba(255,255,255,0.45);
  font-size: 0.8rem;
  margin-top: 0.3rem;
}

/* ── 14. Scroll Animations ──────────────────────────────────────── */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delay */
.fade-up[data-delay="1"] { transition-delay: 0.1s; }
.fade-up[data-delay="2"] { transition-delay: 0.2s; }
.fade-up[data-delay="3"] { transition-delay: 0.3s; }
.fade-up[data-delay="4"] { transition-delay: 0.4s; }
.fade-up[data-delay="5"] { transition-delay: 0.5s; }
.fade-up[data-delay="6"] { transition-delay: 0.6s; }

/* ── 15. Loading Spinner ────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 16px; height: 16px;
  border: 2px solid rgba(255,255,255,0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── 16. Scrollbar ──────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: rgba(37,99,235,0.25);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(37,99,235,0.45); }

/* ── 17. Responsive ─────────────────────────────────────────────── */
@media (min-width: 640px) {
  .form-row { grid-template-columns: 1fr 1fr; }
  .hero-stats { gap: 3rem; }
}

@media (min-width: 768px) {
  .kontak-grid { grid-template-columns: 1fr 1.6fr; }
  .hero-stats { justify-content: flex-start; }
}

@media (min-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr 1fr;
    padding: 5rem 0 4rem;
  }
  .hero-visual { display: block; }
  .hero-sub { max-width: 480px; }
}

@media (max-width: 767px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }

  .nav-links.mobile-open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: rgba(255,255,255,0.97);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--glass-border);
    padding: 1rem;
    gap: 0.3rem;
    z-index: 999;
    box-shadow: 0 12px 40px rgba(37,99,235,0.10);
  }
  .nav-links.mobile-open a {
    padding: 0.7rem 1rem;
    font-size: 1rem;
  }
  .avatar-name { display: none; }
}

@media (max-width: 480px) {
  .mapel-grid { grid-template-columns: 1fr; }
  .modal { padding: 1.5rem; }
}