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

:root {
  --navy: #0b1f4b;
  --blue: #1a3a8f;
  --accent: #e8a838;
  --teal: #0d8c7b;
  --coral: #d4553a;
  --violet: #5b3fa6;
  --cream: #fdf8f0;
  --gray50: #f7f7f5;
  --gray100: #ebebea;
  --gray400: #9b9b97;
  --gray700: #3d3d3a;
  --text: #1a1a17;
  --shadow: rgba(11, 31, 75, 0.12);
  --card-radius: 18px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", Arial, sans-serif;
  background: var(--cream);
  color: var(--text);
  min-height: 100vh;
}

/* Header */

.app-header {
  position: relative;
  background: var(--navy);
  overflow: hidden;
  padding: 56px 24px 48px;
  text-align: center;
}

.app-header::before,
.app-header::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  opacity: 0.08;
}

.app-header::before {
  width: 420px;
  height: 420px;
  top: -180px;
  left: -120px;
  background: var(--accent);
}

.app-header::after {
  width: 280px;
  height: 280px;
  bottom: -120px;
  right: -60px;
  background: #4fa3e0;
}

.header-inner {
  position: relative;
  z-index: 1;
}

.header-badge {
  display: inline-block;
  background: rgba(232, 168, 56, 0.18);
  color: var(--accent);
  border: 1px solid rgba(232, 168, 56, 0.4);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: 40px;
  margin-bottom: 20px;
}

.app-title {
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 900;
  font-size: clamp(36px, 5vw, 62px);
  color: #ffffff;
  line-height: 1.1;
  letter-spacing: -0.5px;
}

.app-title span {
  color: var(--accent);
}

.app-subtitle {
  margin-top: 14px;
  font-size: 16px;
  color: rgba(255, 255, 255, 0.72);
  font-weight: 400;
  letter-spacing: 0.2px;
}

.app-author {
  display: inline-block;
  margin-top: 16px;
  font-size: 13px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.55);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* Layout */

.container {
  width: 96vw;
  max-width: 1680px;
  margin: 0 auto;
  padding: 40px 28px 60px;
}

.intro-card {
  background: #ffffff;
  border: 1px solid var(--gray100);
  border-radius: var(--card-radius);
  padding: 36px 40px;
  margin-bottom: 32px;
  box-shadow: 0 4px 30px var(--shadow);
  display: flex;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
}

.intro-left {
  flex: 1;
  min-width: 240px;
}

.intro-card h2 {
  font-size: 26px;
  font-weight: 800;
  color: var(--navy);
  margin-bottom: 10px;
}

.intro-card p {
  font-size: 14.5px;
  color: var(--gray400);
  line-height: 1.65;
  max-width: 520px;
}

.home-three-column {
  display: grid;
  grid-template-columns: minmax(330px, 1fr) minmax(390px, 1.15fr) minmax(330px, 1fr);
  gap: 24px;
  align-items: start;
}

.home-center-column {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Main cards */

.test-info,
.practice-area {
  background: #ffffff;
  border: 1px solid var(--gray100);
  border-radius: var(--card-radius);
  padding: 28px 28px 32px;
  box-shadow: 0 4px 30px var(--shadow);
}

.color-block-sets {
  border-top: 4px solid var(--accent);
}

.color-block-reference {
  border-top: 4px solid var(--teal);
}

.color-block-fulltest {
  border-top: 4px solid var(--coral);
}

.color-block-practice {
  border-top: 4px solid var(--violet);
}

.test-info h2,
.practice-area h2 {
  font-size: 20px;
  font-weight: 800;
  color: var(--navy);
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--gray100);
}

/* Buttons */

.section-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 0;
  flex-shrink: 0;
}

button {
  font-family: "Segoe UI", Arial, sans-serif;
  font-size: 15px;
  font-weight: 700;
  border: none;
  border-radius: 10px;
  padding: 11px 22px;
  cursor: pointer;
  transition: all 0.18s ease;
  letter-spacing: 0.1px;
  background: var(--blue);
  color: #ffffff;
}

#btn-nav-listening {
  background: var(--blue);
  color: #ffffff;
}

#btn-nav-structure {
  background: var(--teal);
  color: #ffffff;
}

#btn-nav-reading {
  background: var(--violet);
  color: #ffffff;
}

#btn-nav-listening:hover {
  background: #0f2a6b;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(26, 58, 143, 0.3);
}

#btn-nav-structure:hover {
  background: #09705f;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(13, 140, 123, 0.3);
}

#btn-nav-reading:hover {
  background: #432f80;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(91, 63, 166, 0.3);
}

.btn-full-test {
  background: var(--accent);
  color: var(--navy);
  font-weight: 800;
}

.btn-full-test:hover {
  background: #d4942b;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(232, 168, 56, 0.38);
}

.main-button-active {
  background: #16a34a !important;
  color: #ffffff !important;
  box-shadow: 0 0 0 3px rgba(22, 163, 74, 0.25) !important;
}

.btn-full-test.main-button-active {
  background: #ea580c !important;
  color: #ffffff !important;
  box-shadow: 0 0 0 3px rgba(234, 88, 12, 0.25) !important;
}

button:disabled {
  background: #cbd5e1 !important;
  color: #64748b !important;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

/* Info boxes */

.vertical-info-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.info-box {
  background: var(--gray50);
  border: 1px solid var(--gray100);
  border-radius: 12px;
  padding: 16px 18px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.info-box:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--shadow);
}

.info-box h3 {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.color-block-sets .info-box h3 {
  color: var(--accent);
}

.color-block-reference .info-box h3 {
  color: var(--teal);
}

.color-block-fulltest .info-box h3 {
  color: var(--coral);
}

.color-block-practice .info-box h3 {
  color: var(--violet);
}

.info-box p {
  font-size: 13.5px;
  color: var(--text);
  line-height: 1.6;
  margin: 5px 0;
}

.info-box strong {
  color: var(--text);
}

.stat-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.stat-pill {
  font-size: 11.5px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 20px;
  background: rgba(11, 31, 75, 0.07);
  color: var(--navy);
}

.practice-area p {
  font-size: 14px;
  color: var(--text);
  line-height: 1.7;
}

.practice-note,
.flow-text {
  margin-top: 10px;
}

.muted-note {
  margin-top: 6px;
  font-style: italic;
  opacity: 0.72;
}

/* Dynamic test content */

.question-card,
.passage-card,
.audio-box,
.score-box,
.restart-box {
  background: #ffffff;
  border: 1px solid #d7dde7;
  border-radius: 12px;
  padding: 18px;
  margin: 16px 0;
}

.question-card h3,
.passage-card h3,
.audio-box h3,
.score-box h3,
.restart-box h3 {
  margin-top: 0;
}

.question-meta {
  color: #475569;
  font-size: 14px;
}

.choice {
  display: block;
  background: #f8fafc;
  border: 1px solid #dbe3ef;
  border-radius: 8px;
  padding: 10px;
  margin: 9px 0;
  cursor: pointer;
}

.choice:hover {
  background: #eff6ff;
  border-color: #93c5fd;
}

.choice input {
  margin-right: 8px;
}

.explanation {
  margin-top: 12px;
  line-height: 1.5;
}

.correct {
  color: #16a34a;
  font-weight: bold;
}

.wrong {
  color: #dc2626;
  font-weight: bold;
}

.passage-text {
  line-height: 1.7;
  white-space: pre-line;
}

.audio-box {
  background: #f8fafc;
  border-color: #cbd5e1;
}

.audio-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 14px 0;
}

.audio-status {
  margin-top: 10px;
  font-weight: bold;
  color: #475569;
}

.btn-play {
  background: #2563eb;
  color: #ffffff;
}

.btn-pause {
  background: #f59e0b;
  color: #111827;
}

.btn-resume {
  background: #16a34a;
  color: #ffffff;
}

.btn-stop {
  background: #dc2626;
  color: #ffffff;
}

.btn-play.active,
.btn-pause.active,
.btn-resume.active,
.btn-stop.active {
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
  transform: translateY(-1px);
}

.btn-stop:hover {
  background: #b91c1c;
}

.timer-box {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #ecfeff;
  border: 1px solid #67e8f9;
  border-radius: 10px;
  padding: 14px 18px;
  margin: 16px 0;
}

.timer-box p {
  margin: 5px 0 0;
  color: #475569;
  font-size: 14px;
}

.timer-display {
  font-size: 30px;
  font-weight: bold;
  color: #0e7490;
}

.timer-warning {
  background: #fef9c3;
  border-color: #facc15;
}

.timer-warning .timer-display {
  color: #a16207;
}

.timer-danger {
  background: #fee2e2;
  border-color: #ef4444;
}

.timer-danger .timer-display {
  color: #b91c1c;
}

.score-box {
  background: #f0fdf4;
  border-color: #86efac;
}

.score-box p {
  line-height: 1.5;
}

.restart-box {
  background: #f8fafc;
  border-color: #cbd5e1;
}

.restart-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.btn-restart {
  background: #2563eb;
  color: #ffffff;
}

.btn-shuffle {
  background: #7c3aed;
  color: #ffffff;
}

.btn-shuffle:hover {
  background: #5b21b6;
}

/* Footer */

.app-footer {
  text-align: center;
  padding: 32px 24px 40px;
  font-size: 13px;
  color: var(--gray400);
  line-height: 1.8;
  border-top: 1px solid var(--gray100);
  margin-top: 20px;
}

.app-footer a {
  color: var(--blue);
  text-decoration: none;
  font-weight: 600;
}

.app-footer a:hover {
  text-decoration: underline;
}

.footer-contact {
  margin-top: 6px;
}

code {
  background: #e5e7eb;
  color: #111827;
  padding: 2px 5px;
  border-radius: 4px;
}

/* Responsive */

@media (max-width: 1100px) {
  .home-three-column {
    grid-template-columns: 1fr 1fr;
  }

  .home-three-column > .test-info:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 720px) {
  .app-header {
    padding: 42px 18px 36px;
  }

  .app-title {
    font-size: 34px;
  }

  .app-subtitle {
    font-size: 14px;
  }

  .home-three-column {
    grid-template-columns: 1fr;
  }

  .intro-card {
    flex-direction: column;
    align-items: stretch;
    gap: 24px;
    padding: 28px 22px;
  }

  .section-buttons {
    flex-direction: column;
  }

  .section-buttons button,
  .audio-controls button,
  .restart-buttons button {
    width: 100%;
  }

  .container {
    width: 100%;
    padding: 24px 16px 48px;
  }

  .test-info,
  .practice-area {
    padding: 22px 20px 26px;
  }

  .timer-box {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .timer-display {
    font-size: 26px;
  }
}