/* ===========================
   RESET & BASE
=========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Plus Jakarta Sans', sans-serif;
  background: #f8f9ff;
  color: #1e1b4b;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ===========================
   UTILITIES
=========================== */
.container { max-width: 1100px; margin: 0 auto; padding: 0 1.5rem; }
.gradient-text {
  background: linear-gradient(135deg, #6366f1 0%, #ec4899 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===========================
   NAVBAR
=========================== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(99,102,241,0.1);
  transition: box-shadow 0.3s;
}
.navbar.scrolled { box-shadow: 0 4px 24px rgba(99,102,241,0.12); }
.nav-container {
  max-width: 1100px; margin: 0 auto; padding: 0 1.5rem;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.nav-logo {
  display: flex; align-items: center; gap: 8px;
  text-decoration: none; font-weight: 800; font-size: 1.2rem;
  color: #1e1b4b; letter-spacing: -0.5px;
}
.logo-icon {
  width: 34px; height: 34px;
  background: linear-gradient(135deg, #6366f1, #ec4899);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  color: white; font-size: 1rem; font-weight: 700;
}
.logo-accent { color: #6366f1; }
.nav-links {
  display: flex; gap: 0.25rem; list-style: none;
}
.nav-link {
  text-decoration: none; color: #6b7280; font-weight: 500; font-size: 0.9rem;
  padding: 6px 14px; border-radius: 8px; transition: all 0.2s;
}
.nav-link:hover { background: #f3f4ff; color: #6366f1; }
.hamburger {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 4px;
}
.hamburger span {
  display: block; width: 22px; height: 2px;
  background: #6366f1; border-radius: 2px; transition: all 0.3s;
}

/* ===========================
   HERO
=========================== */
.hero {
  min-height: 100vh; padding: 100px 1.5rem 60px;
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, #fafaff 0%, #fdf2ff 50%, #fff7ed 100%);
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.circle-deco {
  position: absolute; border-radius: 50%; opacity: 0.18;
  animation: floatDeco 8s ease-in-out infinite;
}
.c1 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, #6366f1, transparent 70%);
  top: -100px; left: -120px; animation-delay: 0s;
}
.c2 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, #ec4899, transparent 70%);
  top: 60px; right: -80px; animation-delay: 2s;
}
.c3 {
  width: 200px; height: 200px;
  background: radial-gradient(circle, #f59e0b, transparent 70%);
  bottom: 80px; left: 30%; animation-delay: 4s;
}
.c4 {
  width: 150px; height: 150px;
  background: radial-gradient(circle, #10b981, transparent 70%);
  bottom: 40px; right: 20%; animation-delay: 6s;
}
@keyframes floatDeco {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-20px) scale(1.05); }
}

.hero { flex-direction: row; gap: 3rem; }
.hero-content { flex: 1; max-width: 560px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: white; border: 1px solid rgba(99,102,241,0.2);
  border-radius: 50px; padding: 6px 16px; font-size: 0.82rem;
  font-weight: 600; color: #6366f1; margin-bottom: 1.5rem;
  box-shadow: 0 2px 12px rgba(99,102,241,0.1);
}
.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800; line-height: 1.15;
  letter-spacing: -1px; margin-bottom: 1.25rem;
}
.hero-desc {
  font-size: 1.05rem; color: #6b7280; margin-bottom: 2rem;
  max-width: 480px; line-height: 1.7;
}
.hero-btns { display: flex; gap: 1rem; margin-bottom: 2.5rem; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 12px 24px; border-radius: 12px; font-size: 0.95rem;
  font-weight: 600; text-decoration: none; cursor: pointer;
  border: none; transition: all 0.2s; font-family: inherit;
}
.btn-primary {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white; box-shadow: 0 4px 16px rgba(99,102,241,0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(99,102,241,0.4); }
.btn-outline {
  background: white; color: #6366f1;
  border: 2px solid rgba(99,102,241,0.3);
}
.btn-outline:hover { border-color: #6366f1; background: #f3f4ff; }

.hero-stats { display: flex; align-items: center; gap: 1.5rem; }
.stat { display: flex; flex-direction: column; }
.stat-num { font-size: 1.8rem; font-weight: 800; color: #6366f1; line-height: 1; }
.stat-label { font-size: 0.78rem; color: #9ca3af; font-weight: 500; margin-top: 2px; }
.stat-divider { width: 1px; height: 36px; background: #e5e7eb; }

/* Hero Visual */
.hero-visual { flex: 1; display: flex; justify-content: center; align-items: center; }
.circle-main { position: relative; width: 320px; height: 320px; }
.circle-svg { width: 100%; height: 100%; filter: drop-shadow(0 8px 32px rgba(99,102,241,0.15)); }
.formula-float {
  position: absolute; background: white;
  border-radius: 10px; padding: 6px 14px;
  font-family: 'JetBrains Mono', monospace; font-size: 0.85rem; font-weight: 600;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  animation: floatFormula 4s ease-in-out infinite;
}
.f1 { top: 10px; left: -20px; color: #6366f1; animation-delay: 0s; }
.f2 { bottom: 30px; right: -10px; color: #ec4899; animation-delay: 1.5s; }
.f3 { bottom: 90px; left: -30px; color: #f59e0b; animation-delay: 3s; }
@keyframes floatFormula {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ===========================
   SECTIONS
=========================== */
.section { padding: 80px 0; }
.section-alt { background: #f3f4ff; }

.section-header { text-align: center; margin-bottom: 3rem; }
.section-tag {
  display: inline-block; background: white;
  border: 1px solid rgba(99,102,241,0.2);
  border-radius: 50px; padding: 5px 16px;
  font-size: 0.82rem; font-weight: 600; color: #6366f1;
  margin-bottom: 0.75rem;
}
.section-alt .section-tag { background: white; }
.section-title { font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 800; margin-bottom: 0.75rem; letter-spacing: -0.5px; }
.section-desc { color: #6b7280; font-size: 1rem; }

/* ===========================
   MATERI CARDS
=========================== */
.materi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}
.materi-card {
  background: white; border-radius: 16px; padding: 1.75rem;
  box-shadow: 0 2px 16px rgba(99,102,241,0.07);
  border: 1px solid rgba(99,102,241,0.08);
  position: relative; overflow: hidden;
  transition: transform 0.25s, box-shadow 0.25s;
}
.materi-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(99,102,241,0.14);
}
.card-wide { grid-column: 1 / -1; }
.card-header-strip {
  position: absolute; top: 0; left: 0; right: 0; height: 4px;
  border-radius: 16px 16px 0 0;
}
.strip-purple { background: linear-gradient(90deg, #6366f1, #8b5cf6); }
.strip-pink   { background: linear-gradient(90deg, #ec4899, #f472b6); }
.strip-yellow { background: linear-gradient(90deg, #f59e0b, #fbbf24); }
.strip-green  { background: linear-gradient(90deg, #10b981, #34d399); }
.strip-orange { background: linear-gradient(90deg, #f97316, #fb923c); }
.strip-blue   { background: linear-gradient(90deg, #3b82f6, #60a5fa); }

.card-num {
  font-family: 'JetBrains Mono', monospace; font-size: 0.75rem;
  font-weight: 600; color: #c4b5fd; letter-spacing: 1px;
  margin-bottom: 0.5rem; margin-top: 0.25rem;
}
.materi-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 0.75rem; color: #1e1b4b; }
.materi-card p { font-size: 0.92rem; color: #6b7280; line-height: 1.65; }

.card-visual-mini { display: flex; justify-content: center; margin: 1rem 0; }
.rumus-pills { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 1rem; }
.pill {
  padding: 4px 12px; border-radius: 50px; font-size: 0.8rem;
  font-weight: 600; font-family: 'JetBrains Mono', monospace;
}
.pill.purple { background: #ede9fe; color: #6366f1; }
.pill.yellow { background: #fef3c7; color: #d97706; }
.pill.pink   { background: #fce7f3; color: #ec4899; }
.pill.green  { background: #d1fae5; color: #059669; }

.unsur-list { margin-top: 0.75rem; display: flex; flex-direction: column; gap: 0.5rem; }
.unsur-item { display: flex; align-items: flex-start; gap: 10px; font-size: 0.88rem; color: #374151; }
.unsur-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; margin-top: 4px; }

.rumus-box {
  border-radius: 12px; padding: 1rem 1.25rem; margin: 1rem 0; text-align: center;
}
.rumus-purple { background: linear-gradient(135deg, #ede9fe, #e0e7ff); border: 1px solid rgba(99,102,241,0.15); }
.rumus-pink   { background: linear-gradient(135deg, #fce7f3, #fdf2ff); border: 1px solid rgba(236,72,153,0.15); }
.rumus-yellow { background: linear-gradient(135deg, #fef3c7, #fff7ed); border: 1px solid rgba(245,158,11,0.15); }
.rumus-green  { background: linear-gradient(135deg, #d1fae5, #ecfdf5); border: 1px solid rgba(16,185,129,0.15); }
.rumus-orange { background: linear-gradient(135deg, #ffedd5, #fff7ed); border: 1px solid rgba(249,115,22,0.15); }
.rumus-blue   { background: linear-gradient(135deg, #dbeafe, #eff6ff); border: 1px solid rgba(59,130,246,0.15); }
.rumus-big {
  font-family: 'JetBrains Mono', monospace; font-size: 1.05rem; font-weight: 600; color: #1e1b4b;
}
.rumus-label { font-size: 0.75rem; color: #9ca3af; font-weight: 600; margin-bottom: 4px; letter-spacing: 0.5px; }

.contoh-mini { background: #f9fafb; border-radius: 10px; padding: 0.75rem 1rem; margin-top: 0.5rem; border-left: 3px solid #6366f1; }
.contoh-mini-title { font-size: 0.78rem; font-weight: 700; color: #6366f1; margin-bottom: 4px; }
.contoh-mini p { font-size: 0.87rem; color: #374151; margin: 0; }

.persamaan-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.full-width { width: 100%; }
.sudut-wrapper { display: flex; align-items: center; gap: 1.5rem; flex-wrap: wrap; }
.sudut-visual { flex-shrink: 0; }

/* ===========================
   CONTOH SOAL
=========================== */
.soal-list { display: flex; flex-direction: column; gap: 1.25rem; }
.soal-card {
  background: white; border-radius: 16px; padding: 1.75rem;
  box-shadow: 0 2px 16px rgba(99,102,241,0.07);
  border: 1px solid rgba(99,102,241,0.08);
  transition: box-shadow 0.2s;
}
.soal-card:hover { box-shadow: 0 8px 28px rgba(99,102,241,0.12); }
.soal-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1rem; }
.soal-badge {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white; border-radius: 8px; padding: 4px 14px;
  font-size: 0.8rem; font-weight: 700; letter-spacing: 0.5px;
}
.soal-topik {
  background: #f3f4ff; color: #6366f1; border-radius: 8px;
  padding: 4px 12px; font-size: 0.8rem; font-weight: 600;
}
.soal-teks { font-size: 0.95rem; color: #374151; line-height: 1.7; margin-bottom: 1.25rem; }

.btn-toggle {
  display: flex; align-items: center; gap: 8px;
  background: none; border: 2px solid rgba(99,102,241,0.25);
  color: #6366f1; border-radius: 10px; padding: 8px 18px;
  font-size: 0.88rem; font-weight: 600; cursor: pointer;
  transition: all 0.2s; font-family: inherit;
}
.btn-toggle:hover { background: #f3f4ff; border-color: #6366f1; }
.toggle-icon { transition: transform 0.3s; display: inline-block; }

.pembahasan {
  max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
}
.pembahasan.open { max-height: 600px; }
.pembahasan-inner {
  margin-top: 1rem; padding: 1.25rem;
  background: #fafaff; border-radius: 12px;
  border: 1px solid rgba(99,102,241,0.12);
}
.step-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 0.75rem; margin-bottom: 1rem; }
.step { background: white; border-radius: 10px; padding: 0.85rem; border: 1px solid #e5e7eb; }
.step-label {
  font-size: 0.72rem; font-weight: 700; color: #6366f1;
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 6px;
}
.step-content { font-size: 0.88rem; color: #374151; line-height: 1.6; }
.jawaban-final {
  background: linear-gradient(135deg, #d1fae5, #ecfdf5);
  border: 1px solid rgba(16,185,129,0.2);
  border-radius: 10px; padding: 0.75rem 1rem;
  font-size: 0.9rem; font-weight: 600; color: #065f46; text-align: center;
}

/* ===========================
   QUIZ
=========================== */
.quiz-wrapper {
  max-width: 680px; margin: 0 auto;
  background: white; border-radius: 20px; padding: 2rem;
  box-shadow: 0 4px 32px rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.1);
}
.quiz-top { margin-bottom: 1.5rem; }
.quiz-progress-info {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 0.88rem; font-weight: 600; color: #6b7280; margin-bottom: 0.75rem;
}
.quiz-score-badge {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white; border-radius: 50px; padding: 3px 14px; font-size: 0.82rem;
}
.quiz-progress-bar {
  height: 8px; background: #e5e7eb; border-radius: 50px; overflow: hidden;
}
.quiz-progress-fill {
  height: 100%; border-radius: 50px;
  background: linear-gradient(90deg, #6366f1, #ec4899);
  transition: width 0.4s ease;
}

.quiz-card { margin-bottom: 1.5rem; }
.quiz-num {
  font-family: 'JetBrains Mono', monospace; font-size: 0.75rem;
  font-weight: 600; color: #c4b5fd; letter-spacing: 1px; margin-bottom: 0.5rem;
}
.quiz-question { font-size: 1.05rem; font-weight: 600; color: #1e1b4b; margin-bottom: 1.25rem; line-height: 1.6; }
.quiz-options { display: flex; flex-direction: column; gap: 0.6rem; }
.quiz-option {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; border-radius: 12px;
  border: 2px solid #e5e7eb; cursor: pointer;
  font-size: 0.92rem; font-weight: 500; color: #374151;
  transition: all 0.2s; background: white;
  text-align: left; font-family: inherit; width: 100%;
}
.quiz-option:hover:not(:disabled) { border-color: #6366f1; background: #f3f4ff; color: #6366f1; }
.quiz-option.correct { border-color: #10b981; background: #d1fae5; color: #065f46; }
.quiz-option.wrong { border-color: #ef4444; background: #fee2e2; color: #991b1b; }
.quiz-option:disabled { cursor: not-allowed; }
.option-letter {
  width: 28px; height: 28px; border-radius: 8px;
  background: #f3f4ff; color: #6366f1; font-weight: 700;
  font-size: 0.82rem; display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; transition: all 0.2s;
}
.quiz-option.correct .option-letter { background: #10b981; color: white; }
.quiz-option.wrong .option-letter { background: #ef4444; color: white; }

.quiz-feedback {
  margin-top: 0.75rem; font-size: 0.88rem; font-weight: 600;
  padding: 8px 14px; border-radius: 10px; display: none;
}
.quiz-feedback.show-correct { display: block; background: #d1fae5; color: #065f46; }
.quiz-feedback.show-wrong   { display: block; background: #fee2e2; color: #991b1b; }

.quiz-nav { display: flex; justify-content: space-between; gap: 1rem; }
.quiz-nav .btn { flex: 1; justify-content: center; }

.quiz-result {
  text-align: center; padding: 2rem 1rem;
}
.result-icon { font-size: 3.5rem; margin-bottom: 0.75rem; }
.result-title { font-size: 1.5rem; font-weight: 800; margin-bottom: 0.5rem; }
.result-score {
  font-size: 3rem; font-weight: 800;
  background: linear-gradient(135deg, #6366f1, #ec4899);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text; margin-bottom: 0.75rem;
}
.result-msg { font-size: 0.95rem; color: #6b7280; margin-bottom: 1.5rem; }

/* ===========================
   KALKULATOR
=========================== */
.kalkulator-wrapper {
  max-width: 800px; margin: 0 auto;
  background: white; border-radius: 20px; padding: 2rem;
  box-shadow: 0 4px 32px rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.1);
}
.kalkulator-input-box { margin-bottom: 1.75rem; }
.kalkulator-input-box label { font-weight: 700; font-size: 0.95rem; color: #1e1b4b; display: block; margin-bottom: 0.6rem; }
.input-group { display: flex; align-items: center; gap: 0; margin-bottom: 1rem; }
.input-group input {
  flex: 1; padding: 14px 18px; border-radius: 12px 0 0 12px;
  border: 2px solid #e5e7eb; font-size: 1.05rem; font-family: inherit;
  color: #1e1b4b; outline: none; transition: border-color 0.2s;
}
.input-group input:focus { border-color: #6366f1; }
.input-unit {
  padding: 14px 18px; background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white; font-weight: 700; border-radius: 0 12px 12px 0;
  font-size: 0.95rem;
}
.pi-toggle { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; }
.pi-toggle span { font-size: 0.9rem; font-weight: 600; color: #6b7280; }
.pi-btn {
  padding: 6px 16px; border-radius: 8px; font-size: 0.85rem; font-weight: 600;
  cursor: pointer; border: 2px solid #e5e7eb; background: white;
  color: #6b7280; transition: all 0.2s; font-family: 'JetBrains Mono', monospace;
}
.pi-btn.active { background: #6366f1; border-color: #6366f1; color: white; }
.pi-btn:hover:not(.active) { border-color: #6366f1; color: #6366f1; }

.kalkulator-hasil {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem;
}
.hasil-card {
  border-radius: 14px; padding: 1.25rem; text-align: center;
}
.hc-purple { background: linear-gradient(135deg, #ede9fe, #e0e7ff); }
.hc-pink   { background: linear-gradient(135deg, #fce7f3, #fdf2ff); }
.hc-yellow { background: linear-gradient(135deg, #fef3c7, #fff7ed); }
.hc-green  { background: linear-gradient(135deg, #d1fae5, #ecfdf5); }
.hasil-label { font-size: 0.78rem; font-weight: 700; color: #9ca3af; text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 0.4rem; }
.hasil-nilai { font-size: 1.4rem; font-weight: 800; color: #1e1b4b; margin-bottom: 0.25rem; font-family: 'JetBrains Mono', monospace; }
.hasil-rumus { font-size: 0.72rem; font-family: 'JetBrains Mono', monospace; color: #9ca3af; }

/* ===========================
   RANGKUMAN
=========================== */
.rangkuman-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 1rem;
  margin-bottom: 1.5rem;
}
.rang-card {
  border-radius: 14px; padding: 1.25rem 1.5rem;
  display: flex; flex-direction: column; gap: 0.5rem;
  transition: transform 0.2s;
}
.rang-card:hover { transform: translateY(-3px); }
.rc1 { background: linear-gradient(135deg, #ede9fe, #e0e7ff); }
.rc2 { background: linear-gradient(135deg, #fce7f3, #fdf2ff); }
.rc3 { background: linear-gradient(135deg, #fef3c7, #fff7ed); }
.rc4 { background: linear-gradient(135deg, #d1fae5, #ecfdf5); }
.rc5 { background: linear-gradient(135deg, #dbeafe, #eff6ff); }
.rc6 { background: linear-gradient(135deg, #ffedd5, #fff7ed); }
.rang-num { font-size: 0.75rem; font-weight: 700; color: #9ca3af; letter-spacing: 1px; }
.rang-title { font-size: 0.95rem; font-weight: 700; color: #1e1b4b; }
.rang-rumus { font-family: 'JetBrains Mono', monospace; font-size: 0.88rem; font-weight: 600; color: #6366f1; }
.pi-note {
  text-align: center; background: white; border: 1px solid rgba(99,102,241,0.15);
  border-radius: 12px; padding: 10px 24px; display: inline-block;
  font-family: 'JetBrains Mono', monospace; font-size: 0.88rem; font-weight: 600;
  color: #6366f1; margin: 0 auto; display: block; width: fit-content;
}

/* ===========================
   TENTANG
=========================== */
.tentang-card {
  background: white; border-radius: 20px; padding: 2.5rem;
  box-shadow: 0 4px 32px rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.1);
  display: flex; align-items: flex-start; gap: 2.5rem;
  max-width: 800px; margin: 0 auto;
}
.tentang-avatar { flex-shrink: 0; display: flex; justify-content: center; }
.avatar-ring {
  width: 100px; height: 100px; border-radius: 50%;
  background: linear-gradient(135deg, #6366f1, #ec4899);
  padding: 3px; box-shadow: 0 8px 24px rgba(99,102,241,0.3);
}
.avatar-inner {
  width: 100%; height: 100%; border-radius: 50%;
  background: white; display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; font-weight: 800; color: #6366f1;
  letter-spacing: 1px;
}
.tentang-info h3 { font-size: 1.5rem; font-weight: 800; margin-bottom: 0.75rem; }
.tentang-badges { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 1rem; }
.tbadge {
  padding: 4px 12px; border-radius: 50px; font-size: 0.78rem; font-weight: 600;
}
.tbadge-purple { background: #ede9fe; color: #6366f1; }
.tbadge-pink   { background: #fce7f3; color: #ec4899; }
.tbadge-green  { background: #d1fae5; color: #059669; }
.tentang-bio { font-size: 0.92rem; color: #6b7280; line-height: 1.7; margin-bottom: 1.25rem; }
.tentang-detail { display: flex; flex-direction: column; gap: 0.5rem; }
.detail-item { display: flex; align-items: center; gap: 8px; font-size: 0.88rem; color: #374151; font-weight: 500; }

/* ===========================
   FOOTER
=========================== */
.footer {
  background: #1e1b4b; color: white; padding-top: 3rem;
}
.footer-container {
  max-width: 1100px; margin: 0 auto; padding: 0 1.5rem 2.5rem;
  display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 2rem;
}
.footer-brand .nav-logo { color: white; margin-bottom: 0.75rem; display: inline-flex; }
.footer-brand p { font-size: 0.88rem; color: rgba(255,255,255,0.5); }
.footer-links { display: flex; flex-direction: column; gap: 0.5rem; }
.footer-link-title { font-size: 0.8rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: rgba(255,255,255,0.4); margin-bottom: 0.25rem; }
.footer-links a { color: rgba(255,255,255,0.65); font-size: 0.9rem; text-decoration: none; transition: color 0.2s; }
.footer-links a:hover { color: #a5b4fc; }
.footer-quote { border-left: 3px solid #6366f1; padding-left: 1rem; }
.quote-mark { font-size: 2rem; color: #6366f1; line-height: 1; margin-bottom: 0.25rem; }
.footer-quote div:last-child { font-size: 0.88rem; color: rgba(255,255,255,0.6); font-style: italic; line-height: 1.6; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 1.25rem 1.5rem; text-align: center;
}
.footer-bottom p { font-size: 0.82rem; color: rgba(255,255,255,0.4); }

/* ===========================
   RESPONSIVE
=========================== */
@media (max-width: 768px) {
  .hero { flex-direction: column; text-align: center; padding: 90px 1.5rem 50px; }
  .hero-desc { max-width: 100%; }
  .hero-btns { justify-content: center; }
  .hero-stats { justify-content: center; }
  .hero-visual { display: none; }
  .nav-links { display: none; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: white; padding: 1rem 1.5rem; border-bottom: 1px solid #e5e7eb; box-shadow: 0 8px 24px rgba(0,0,0,0.1); }
  .nav-links.open { display: flex; }
  .hamburger { display: flex; }
  .card-wide { grid-column: auto; }
  .persamaan-grid { grid-template-columns: 1fr; }
  .tentang-card { flex-direction: column; align-items: center; text-align: center; padding: 1.75rem; }
  .tentang-badges { justify-content: center; }
  .tentang-detail { align-items: center; }
  .footer-container { grid-template-columns: 1fr; }
  .sudut-wrapper { flex-direction: column; }
  .quiz-nav { flex-direction: column; }
}

@media (max-width: 480px) {
  .materi-grid { grid-template-columns: 1fr; }
  .step-grid { grid-template-columns: 1fr; }
  .kalkulator-hasil { grid-template-columns: 1fr 1fr; }
  .rangkuman-grid { grid-template-columns: 1fr 1fr; }
}

/* ===========================
   SCROLL ANIMATION
=========================== */
.fade-in {
  opacity: 0; transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.fade-in.visible { opacity: 1; transform: translateY(0); }