:root {
  --bg: #f2f7fb;
  --surface: #ffffff;
  --ink: #132033;
  --muted: #667085;
  --line: #dbe7f1;
  --primary: #0b3f98;
  --secondary: #007d82;
  --accent: #d9a441;
  --success: #128a63;
  --danger: #d93a4a;
  --radius: 22px;
  --shadow: 0 18px 45px rgba(23, 32, 51, .08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(11, 63, 152, .13), transparent 32rem),
    radial-gradient(circle at top right, rgba(0, 125, 130, .12), transparent 30rem),
    linear-gradient(135deg, #f9fcff 0%, #eaf3ff 46%, #eaf8f7 100%);
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px clamp(16px, 4vw, 54px);
  background: rgba(255, 255, 255, .82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(228, 232, 244, .8);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  min-width: 0;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: #fff;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  box-shadow: 0 12px 28px rgba(11, 63, 152, .24);
}

.brand strong, .brand small {
  display: block;
}

.brand small {
  color: var(--muted);
  font-weight: 700;
}

.top-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.top-nav a {
  padding: 10px 12px;
  border-radius: 999px;
  color: #2d3652;
  font-weight: 800;
}

.top-nav a:hover {
  background: #eef1ff;
  color: var(--primary);
}

.nav-btn {
  border: 0;
  cursor: pointer;
  padding: 10px 12px;
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  font: inherit;
  font-weight: 900;
}

.nav-class {
  border: 1px solid rgba(217, 164, 65, .32);
  cursor: pointer;
  padding: 10px 12px;
  border-radius: 999px;
  background: #fff8e8;
  color: #835b05;
  font: inherit;
  font-weight: 900;
}

.nav-user {
  padding: 10px 12px;
  border-radius: 999px;
  background: #eef1ff;
  color: var(--primary);
  font-weight: 900;
}

main {
  width: min(1160px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, .95fr);
  gap: 24px;
  align-items: center;
  padding: clamp(28px, 6vw, 68px) 0 28px;
}

.eyebrow {
  display: inline-flex;
  padding: 8px 12px;
  border-radius: 999px;
  background: #fff;
  color: var(--primary);
  font-weight: 900;
  border: 1px solid var(--line);
}

h1, h2, h3 {
  letter-spacing: 0;
  line-height: 1.08;
}

h1 {
  margin: 14px 0;
}

.hero p, .section-lead {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.hero-panel, .card, .question-card, .search-box {
  background: rgba(255, 255, 255, .92);
  border: 1px solid rgba(228, 232, 244, .9);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-panel {
  padding: 22px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.stat {
  padding: 16px;
  border-radius: 18px;
  background: #f8faff;
}

.stat strong {
  display: block;
  font-size: 24px;
}

.actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 22px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 16px;
  border-radius: 15px;
  font-weight: 900;
  background: #eef1ff;
  color: var(--primary);
}

.btn.primary {
  background: var(--primary);
  color: #fff;
}

.search-box {
  padding: 12px;
  display: flex;
  gap: 8px;
  margin: 22px 0;
}

.search-box input {
  flex: 1;
  border: 0;
  outline: 0;
  background: transparent;
  font: inherit;
  min-width: 0;
  padding: 10px;
}

.search-box button {
  border: 0;
  cursor: pointer;
}

.section-title {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 12px;
  margin: 28px 0 14px;
}

.section-title h2 {
  margin: 0;
  font-size: clamp(24px, 4vw, 36px);
}

.grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.card {
  padding: 18px;
  transition: transform .18s ease, box-shadow .18s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 22px 55px rgba(23, 32, 51, .12);
}

.icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: #fff;
  border-radius: 16px;
  font-weight: 900;
  background: var(--primary);
}

.muted {
  color: var(--muted);
}

.question-list {
  display: grid;
  gap: 14px;
  margin-bottom: 34px;
}

.question-card {
  padding: 20px;
}

.question-card h2 {
  font-size: 21px;
  margin: 12px 0 8px;
}

.question-card h1 {
  font-size: clamp(26px, 5vw, 46px);
  margin: 10px 0;
}

.hindi {
  color: #344054;
  font-weight: 700;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--muted);
  font-weight: 800;
  font-size: 13px;
}

.badge {
  display: inline-flex;
  padding: 5px 9px;
  border-radius: 999px;
  color: #fff;
  background: var(--primary);
}

.badge-easy {
  background: var(--success);
}

.badge-medium {
  background: var(--secondary);
}

.badge-hard {
  background: #f97316;
}

.badge-expert {
  background: var(--danger);
}

.options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 14px 0;
}

.options span {
  padding: 12px;
  border-radius: 14px;
  background: #f6f8ff;
  border: 1px solid var(--line);
  font-weight: 800;
}

details {
  border-top: 1px solid var(--line);
  margin-top: 14px;
  padding-top: 12px;
}

summary {
  cursor: pointer;
  font-weight: 900;
  color: var(--primary);
}

.answer-box {
  border-left: 5px solid var(--success);
  background: #ecfdf3;
  padding: 16px;
  border-radius: 16px;
}

.answer-locked {
  margin-top: 14px;
  padding: 16px;
  border-radius: 16px;
  border: 1px dashed rgba(11, 63, 152, .42);
  background: #f3f8ff;
}

.answer-locked p {
  color: var(--muted);
  margin: 6px 0 12px;
}

.auth-modal {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(16, 21, 40, .54);
}

.auth-modal[hidden] {
  display: none;
}

.class-modal {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: grid;
  place-items: center;
  padding: 18px;
  background:
    radial-gradient(circle at 20% 10%, rgba(217, 164, 65, .24), transparent 22rem),
    radial-gradient(circle at 80% 0%, rgba(0, 125, 130, .22), transparent 24rem),
    rgba(7, 20, 36, .70);
  backdrop-filter: blur(10px);
}

.class-modal[hidden] {
  display: none;
}

.class-dialog {
  width: min(560px, 100%);
  padding: 26px;
  border-radius: 26px;
  background: #fff;
  box-shadow: 0 28px 80px rgba(16, 21, 40, .28);
}

.class-dialog h2 {
  margin: 14px 0 8px;
  font-size: clamp(28px, 5vw, 42px);
}

.class-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.class-grid button {
  min-height: 104px;
  border: 1px solid rgba(228, 232, 244, .95);
  cursor: pointer;
  border-radius: 20px;
  padding: 16px;
  text-align: left;
  background: linear-gradient(135deg, #f8fbff, #eef8f7);
  color: var(--ink);
  box-shadow: 0 12px 30px rgba(23, 32, 51, .08);
}

.class-grid button:hover {
  transform: translateY(-2px);
  border-color: rgba(11, 63, 152, .45);
}

.class-grid strong {
  display: block;
  font-size: 22px;
  margin-bottom: 6px;
}

.class-grid span {
  color: var(--muted);
  font-weight: 800;
}

.class-message {
  min-height: 20px;
  color: var(--danger);
  font-weight: 900;
}

.auth-dialog {
  width: min(430px, 100%);
  position: relative;
  padding: 24px;
  border-radius: 24px;
  background: #fff;
  box-shadow: 0 24px 70px rgba(16, 21, 40, .24);
}

.auth-close {
  position: absolute;
  top: 12px;
  right: 12px;
  border: 0;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: #eef1ff;
  color: var(--primary);
  font-size: 22px;
  cursor: pointer;
}

.auth-action {
  width: 100%;
  margin: 12px 0;
}

.otp-box {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.phone-row {
  min-width: 0;
  flex: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  padding: 0 12px;
}

.phone-prefix {
  flex: 0 0 auto;
  color: var(--primary);
  font-weight: 950;
}

.otp-box input {
  min-width: 0;
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px;
  font: inherit;
}

.phone-row input {
  border: 0;
  border-radius: 0;
  padding: 12px 0;
  width: 100%;
  outline: 0;
}

.phone-row:focus-within {
  border-color: rgba(92, 74, 255, .62);
  box-shadow: 0 0 0 4px rgba(92, 74, 255, .11);
}

.auth-message {
  min-height: 20px;
  color: var(--muted);
  font-weight: 800;
}

.auth-message.error {
  color: var(--danger);
}

.alert {
  padding: 12px;
  border-radius: 14px;
  background: #fff8e8;
  color: #835b05;
  font-weight: 800;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 18px;
  align-items: start;
}

.sidebar-card {
  position: sticky;
  top: 88px;
}

.level-links {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.level-links a {
  padding: 8px 10px;
  border-radius: 999px;
  background: #eef1ff;
  color: var(--primary);
  font-weight: 900;
}

.site-footer {
  width: min(1160px, calc(100% - 32px));
  margin: 34px auto 0;
  padding: 24px 0 36px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  border-top: 1px solid rgba(228, 232, 244, .9);
  color: var(--muted);
}

.site-footer nav {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  font-weight: 800;
}

.empty {
  padding: 34px;
  text-align: center;
}

@media (max-width: 900px) {
  .hero, .two-col {
    grid-template-columns: 1fr;
  }

  .grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .sidebar-card {
    position: static;
  }
}

@media (max-width: 560px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .top-nav {
    justify-content: flex-start;
  }

  .grid, .hero-stats, .options {
    grid-template-columns: 1fr;
  }

  .class-grid {
    grid-template-columns: 1fr;
  }

  .search-box {
    flex-direction: column;
  }

  .otp-box {
    flex-direction: column;
  }

  .phone-row {
    width: 100%;
  }

  .site-footer {
    flex-direction: column;
  }
}