:root {
  --ink: #111827;
  --muted: #667085;
  --line: #e4edf8;
  --blue: #12a6df;
  --blue-dark: #087fb2;
  --purple: #7557d8;
  --purple-soft: #f1edff;
  --mint: #38d6a4;
  --gold: #f3ad3d;
  --bg: #f8fcff;
  font-family: Tahoma, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 16% 42%, rgba(18, 166, 223, 0.08), transparent 28rem),
    radial-gradient(circle at 86% 28%, rgba(117, 87, 216, 0.08), transparent 31rem),
    linear-gradient(180deg, #f7fbff 0%, #ffffff 48%, #f7fbff 100%);
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.site-header {
  position: sticky;
  top: 18px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1420px, calc(100% - 28px));
  margin: 0 auto;
  padding: 14px 18px;
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid rgba(228, 237, 248, 0.9);
  border-radius: 24px;
  box-shadow: 0 18px 50px rgba(16, 24, 40, 0.06);
  backdrop-filter: blur(18px);
}

.brand,
.top-menu a,
.secondary-button {
  color: var(--ink);
  text-decoration: none;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 190px;
  color: var(--blue-dark);
  font-size: 1.1rem;
  font-weight: 900;
}

.top-menu {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex: 1;
}

.top-menu a {
  color: #344054;
  border-radius: 14px;
  padding: 13px 18px;
  font-weight: 800;
}

.top-menu a.active {
  color: var(--blue-dark);
  background: #e9f7ff;
}

.header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  min-width: 240px;
}

.login-link,
.primary-button,
.secondary-button {
  border: 0;
  border-radius: 14px;
  padding: 13px 18px;
  font-weight: 900;
}

.login-link,
.primary-button {
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  box-shadow: 0 16px 34px rgba(18, 166, 223, 0.28);
}

.secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--blue-dark);
  background: #e9f7ff;
}

.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 70px;
  width: min(1420px, calc(100% - 32px));
  min-height: calc(100vh - 112px);
  margin: 0 auto;
  padding: 76px 0 84px;
}

.hero-copy {
  justify-self: end;
  max-width: 640px;
}

.eyebrow,
.section-chip,
.soft-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  width: fit-content;
  padding: 8px 14px;
  color: #91610f;
  background: #fff7e8;
  border: 1px solid #f8e4bd;
  border-radius: 999px;
  font-weight: 900;
  font-size: 0.86rem;
}

.eyebrow::before {
  content: "";
  width: 9px;
  height: 9px;
  border-radius: 999px;
  background: var(--gold);
}

h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(3.2rem, 5.8vw, 6.1rem);
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-copy h1 {
  max-width: 760px;
}

.hero-copy h1 span {
  color: var(--blue);
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(2rem, 4vw, 3.1rem);
  line-height: 1.16;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.28rem;
}

h4 {
  margin-bottom: 6px;
  font-size: 1.05rem;
}

.hero-copy p:not(.eyebrow),
.steps-grid p,
.course-card p,
.student-course p,
.exam-panel p,
.course-room-head p,
footer span {
  color: var(--muted);
  line-height: 1.8;
}

.hero-copy p:not(.eyebrow) {
  max-width: 660px;
  font-size: 1.22rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 26px;
}

.hero-actions .primary-button {
  min-width: 230px;
  padding: 17px 24px;
  border-radius: 18px;
  font-size: 1.08rem;
}

.hero-stats {
  display: flex;
  gap: 36px;
  margin-top: 52px;
  padding-top: 28px;
  border-top: 1px solid rgba(152, 162, 179, 0.22);
}

.hero-stats span {
  color: #8a94a6;
  line-height: 1.6;
}

.hero-stats strong {
  display: block;
  color: #d28a12;
  font-size: 1.7rem;
}

.hero-art {
  position: relative;
  justify-self: start;
  width: min(620px, 100%);
  min-height: 560px;
  isolation: isolate;
  overflow: visible;
  border-radius: 0;
}

.animated-hero {
  background:
    radial-gradient(circle at 35% 34%, rgba(18, 166, 223, 0.12), transparent 15rem),
    radial-gradient(circle at 68% 62%, rgba(117, 87, 216, 0.12), transparent 17rem);
  border: 0;
  box-shadow: none;
}

.hero-glow {
  position: absolute;
  width: 190px;
  height: 190px;
  border-radius: 50%;
  filter: blur(18px);
  opacity: 0.35;
  animation: driftGlow 9s ease-in-out infinite alternate;
}

.glow-blue {
  top: 12%;
  left: 14%;
  background: var(--blue);
}

.glow-purple {
  right: 12%;
  bottom: 10%;
  background: var(--purple);
  animation-delay: -3s;
}

.orbit {
  position: absolute;
  inset: 9%;
  border: 1px dashed rgba(152, 162, 179, 0.18);
  border-radius: 50%;
  animation: rotateHero 18s linear infinite;
}

.orbit-two {
  inset: 20%;
  border-color: rgba(18, 166, 223, 0.16);
  animation-duration: 13s;
  animation-direction: reverse;
}

.orbit-three {
  inset: 30%;
  border-style: dashed;
  border-color: rgba(243, 173, 61, 0.28);
  animation-duration: 10s;
}

.core {
  position: absolute;
  top: 50%;
  left: 50%;
  display: grid;
  place-items: center;
  width: 160px;
  height: 160px;
  transform: translate(-50%, -50%);
  color: var(--blue-dark);
  background: white;
  border-radius: 50%;
  font-weight: 900;
  box-shadow: 0 22px 70px rgba(16, 24, 40, 0.12);
  animation: corePulse 3.8s ease-in-out infinite;
}

.core span,
.core small {
  display: block;
  text-align: center;
}

.core span {
  font-size: 2.1rem;
  letter-spacing: 0;
}

.core small {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.82rem;
}

.float-card {
  position: absolute;
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 10px;
  align-items: center;
  min-width: 184px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 18px 44px rgba(16, 24, 40, 0.1);
  animation: floatCard 5.6s ease-in-out infinite;
}

.float-card small {
  grid-column: 2;
  color: var(--muted);
}

.mini-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  font-weight: 900;
}

.blue {
  color: var(--blue-dark);
  background: #e5f6ff;
}

.purple {
  color: var(--purple);
  background: var(--purple-soft);
}

.mint {
  color: #087c61;
  background: #dcfff3;
}

.gold {
  color: #a76406;
  background: #fff2d9;
}

.card-a {
  top: 14%;
  right: -3%;
}

.card-b {
  top: 15%;
  left: 1%;
  animation-delay: -1.4s;
}

.card-c {
  bottom: 10%;
  right: -3%;
  animation-delay: -2.2s;
}

.card-d {
  bottom: 10%;
  left: 0;
  animation-delay: -3.1s;
}

.spark {
  position: absolute;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 8px rgba(243, 173, 61, 0.1);
  animation: sparkle 4s ease-in-out infinite;
}

.spark-one {
  top: 18%;
  left: 42%;
}

.spark-two {
  top: 49%;
  right: 15%;
  background: var(--blue);
  animation-delay: -1s;
}

.spark-three {
  bottom: 22%;
  left: 30%;
  background: var(--purple);
  animation-delay: -2s;
}

.spark-four {
  top: 64%;
  left: 58%;
  background: var(--mint);
  animation-delay: -3s;
}

.section,
.student-shell,
.registration-steps,
.auto-solve-section {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 86px 0;
}

.auto-solve-section {
  display: grid;
  grid-template-columns: 0.75fr 1.25fr;
  align-items: center;
  gap: 36px;
  padding-top: 18px;
}

.auto-solve-copy h2 {
  margin-top: 18px;
  max-width: 420px;
}

.auto-solve-copy p:not(.section-chip) {
  max-width: 440px;
  color: var(--muted);
  line-height: 1.8;
  font-size: 1.08rem;
}

.question-demo {
  position: relative;
  overflow: hidden;
  padding: 18px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: 0 24px 70px rgba(16, 24, 40, 0.09);
}

.question-demo img {
  display: block;
  width: 100%;
  border-radius: 16px;
}

.solver-note {
  position: absolute;
  right: 38px;
  padding: 10px 14px;
  color: var(--blue-dark);
  background: rgba(233, 247, 255, 0.94);
  border: 1px solid #ccecff;
  border-radius: 999px;
  font-weight: 900;
  box-shadow: 0 14px 34px rgba(18, 166, 223, 0.14);
  opacity: 0;
  transform: translateY(12px);
  animation: solveNote 6s ease-in-out infinite;
}

.note-one {
  top: 36%;
}

.note-two {
  top: 48%;
  animation-delay: 1.5s;
}

.answer-ring {
  position: absolute;
  right: 16.5%;
  bottom: 16.5%;
  width: 92px;
  height: 72px;
  border: 4px solid var(--blue);
  border-radius: 999px;
  box-shadow: 0 0 0 10px rgba(18, 166, 223, 0.12);
  opacity: 0;
  transform: scale(0.7);
  animation: answerPop 6s ease-in-out infinite;
  animation-delay: 3s;
}

.answer-badge {
  position: absolute;
  right: 12%;
  bottom: 7%;
  padding: 12px 18px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  border-radius: 999px;
  font-weight: 900;
  box-shadow: 0 18px 38px rgba(18, 166, 223, 0.24);
  opacity: 0;
  transform: translateY(14px);
  animation: answerBadge 6s ease-in-out infinite;
  animation-delay: 3.4s;
}

.section > .section-chip,
.section > h2 {
  margin-right: auto;
  margin-left: auto;
  text-align: center;
}

.steps-grid,
.course-grid,
.student-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 34px;
}

.steps-grid article,
.course-card,
.student-course,
.exam-panel,
.login-modal form {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: 0 18px 50px rgba(16, 24, 40, 0.08);
}

.steps-grid article {
  min-height: 210px;
  padding: 24px;
}

.steps-grid span {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  margin-bottom: 26px;
  color: var(--purple);
  background: var(--purple-soft);
  border-radius: 14px;
  font-weight: 900;
}

.course-card {
  position: relative;
  overflow: hidden;
  display: grid;
  align-content: end;
  min-height: 360px;
  padding: 24px;
}

.course-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(18, 166, 223, 0.18), rgba(117, 87, 216, 0.16));
}

.course-card > * {
  position: relative;
}

.course-visual {
  position: absolute;
  top: 24px;
  left: 24px;
  right: 24px;
  height: 148px;
  border-radius: 18px;
  background:
    radial-gradient(circle at 22% 28%, rgba(255, 255, 255, 0.95) 0 34px, transparent 35px),
    linear-gradient(135deg, rgba(255, 255, 255, 0.35), rgba(255, 255, 255, 0.08));
  border: 1px solid rgba(255, 255, 255, 0.58);
}

.course-image {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  border-radius: 18px;
}

.visual-orb {
  position: absolute;
  top: 34px;
  right: 34px;
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  border-radius: 20px;
  font-size: 1.9rem;
  font-weight: 900;
  box-shadow: 0 18px 34px rgba(18, 166, 223, 0.26);
}

.visual-title {
  position: absolute;
  top: 34px;
  left: 30px;
  padding: 10px 16px;
  color: rgba(17, 24, 39, 0.68);
  background: rgba(255, 255, 255, 0.72);
  border-radius: 999px;
  font-weight: 900;
}

.visual-line {
  position: absolute;
  right: 122px;
  height: 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
}

.line-one {
  top: 42px;
  width: 46%;
}

.line-two {
  top: 70px;
  width: 58%;
}

.line-three {
  top: 98px;
  width: 35%;
}

.foundation-card::before {
  background: linear-gradient(135deg, rgba(56, 214, 164, 0.16), rgba(117, 87, 216, 0.14));
}

.foundation-card .course-visual {
  background:
    radial-gradient(circle at 78% 26%, rgba(255, 255, 255, 0.95) 0 34px, transparent 35px),
    linear-gradient(135deg, rgba(255, 255, 255, 0.42), rgba(255, 255, 255, 0.1));
}

.foundation-card .visual-orb {
  background: linear-gradient(135deg, var(--mint), var(--blue));
}

.course-type {
  display: inline-flex;
  width: fit-content;
  margin-top: 170px;
  margin-bottom: 20px;
  padding: 8px 12px;
  color: white;
  background: rgba(17, 24, 39, 0.58);
  border-radius: 999px;
  font-weight: 900;
}

.course-meta {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid rgba(17, 24, 39, 0.1);
}

.registration-steps {
  display: grid;
  grid-template-columns: 0.82fr 1fr;
  align-items: start;
  gap: 60px;
  padding-top: 36px;
}

.steps-copy {
  position: sticky;
  top: 110px;
  padding-top: 18px;
}

.steps-copy h2 {
  max-width: 420px;
  margin-top: 22px;
  font-size: clamp(2.4rem, 4.5vw, 4.1rem);
}

.steps-copy p:not(.section-chip),
.wide-step p {
  color: var(--muted);
  line-height: 1.8;
}

.steps-copy p:not(.section-chip) {
  max-width: 470px;
  font-size: 1.12rem;
}

.steps-note {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  margin-top: 46px;
  color: #98a2b3;
  font-weight: 800;
}

.steps-note::before {
  content: "";
  width: 70px;
  height: 2px;
  background: #d0d5dd;
}

.steps-list {
  display: grid;
  gap: 28px;
}

.wide-step {
  position: relative;
  display: grid;
  grid-template-columns: 64px 1fr 44px;
  align-items: center;
  gap: 22px;
  min-height: 132px;
  padding: 26px 30px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: 0 18px 54px rgba(16, 24, 40, 0.08);
}

.wide-step::after {
  content: "";
  position: absolute;
  top: 22px;
  left: 0;
  width: 4px;
  height: calc(100% - 44px);
  border-radius: 999px;
  background: var(--blue);
}

.wide-step:nth-child(2) {
  transform: translateX(-28px);
}

.wide-step:nth-child(3) {
  transform: translateX(-56px);
}

.step-icon {
  display: grid;
  place-items: center;
  width: 62px;
  height: 62px;
  border-radius: 16px;
  color: var(--blue-dark);
  background: #e6f7ff;
  font-size: 1.8rem;
  font-weight: 900;
}

.wide-step strong {
  color: #b8c0cc;
}

.step-gold::after {
  background: var(--gold);
}

.step-gold .step-icon {
  color: #a76406;
  background: #fff2d9;
}

.step-mint::after {
  background: var(--mint);
}

.step-mint .step-icon {
  color: #087c61;
  background: #dcfff3;
}

.student-shell[hidden],
.course-room[hidden] {
  display: none;
}

.student-header,
.course-room-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 26px;
}

#courseMeta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.capacity-badge {
  display: inline-flex;
  padding: 8px 14px;
  color: var(--blue-dark);
  background: #e9f7ff;
  border: 1px solid #d7effb;
  border-radius: 999px;
  font-weight: 900;
}

.student-course {
  display: grid;
  gap: 20px;
  padding: 24px;
}

.student-course strong {
  color: var(--blue-dark);
}

.course-room {
  margin-top: 32px;
  padding-top: 40px;
}

.exam-panel {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 24px;
  padding: 26px;
}

.course-gate-head {
  padding: 22px;
  border: 1px solid #dcecff;
  border-radius: 18px;
  background: linear-gradient(135deg, #f4fbff, #f5f0ff);
}

.exam-list {
  display: grid;
  gap: 14px;
}

.course-exam-image {
  display: grid;
  gap: 10px;
  padding: 18px;
  border: 1px solid #dcecff;
  border-radius: 18px;
  background: white;
  box-shadow: 0 16px 42px rgba(16, 24, 40, 0.06);
}

.course-exam-image p {
  margin-bottom: 4px;
  color: var(--muted);
}

.course-exam-image img {
  display: block;
  width: 100%;
  border-radius: 14px;
  border: 1px solid var(--line);
}

.interactive-exam {
  display: grid;
  gap: 22px;
  padding: 24px;
  border: 1px solid #dcecff;
  border-radius: 20px;
  background: white;
  box-shadow: 0 16px 42px rgba(16, 24, 40, 0.06);
}

.exam-cover,
.exam-progress,
.result-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.exam-set-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.exam-set-card {
  display: grid;
  gap: 8px;
  min-height: 150px;
  padding: 18px;
  border: 1px solid #dcecff;
  border-radius: 18px;
  color: var(--ink);
  background: linear-gradient(135deg, #f4fbff, #f8f5ff);
  text-align: right;
}

.exam-set-card span {
  color: var(--blue-dark);
  font-weight: 900;
}

.exam-set-card strong {
  font-size: 1.5rem;
}

.exam-set-card small {
  color: var(--muted);
}

.exam-set-card:hover {
  border-color: var(--blue);
  box-shadow: 0 16px 34px rgba(18, 166, 223, 0.14);
}

.exam-progress {
  color: var(--blue-dark);
  font-weight: 900;
}

.choice-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.question-diagram {
  display: grid;
  place-items: center;
  padding: 14px;
  border: 1px solid #dcecff;
  border-radius: 18px;
  background: linear-gradient(135deg, #f4fbff, #f8f5ff);
}

.question-diagram svg {
  width: min(360px, 100%);
  height: auto;
}

.question-diagram rect,
.question-diagram path {
  fill: rgba(117, 87, 216, 0.1);
  stroke: var(--purple);
  stroke-width: 3;
}

.question-diagram line {
  stroke: var(--blue-dark);
  stroke-width: 3;
  stroke-dasharray: 6 5;
}

.question-diagram circle {
  fill: var(--blue);
}

.question-diagram text {
  fill: var(--blue-dark);
  font-family: Tahoma, Arial, sans-serif;
  font-size: 18px;
  font-weight: 900;
  text-anchor: middle;
}

.choice-button {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 68px;
  padding: 16px;
  border: 1px solid #dcecff;
  border-radius: 16px;
  color: var(--ink);
  background: linear-gradient(135deg, #f4fbff, #f8f5ff);
  font-weight: 900;
  text-align: right;
}

.choice-button span {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  flex: 0 0 34px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  border-radius: 10px;
}

.choice-button:hover {
  border-color: var(--blue);
  box-shadow: 0 12px 30px rgba(18, 166, 223, 0.14);
}

.result-card {
  text-align: center;
}

.result-meter {
  overflow: hidden;
  height: 14px;
  background: #eef4fb;
  border-radius: 999px;
}

.result-meter span {
  display: block;
  height: 100%;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  border-radius: inherit;
}

.review-list {
  display: grid;
  gap: 12px;
}

.review-item {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #f8fbff;
}

.review-item.correct {
  border-color: rgba(56, 214, 164, 0.45);
  background: #f0fff9;
}

.review-item.wrong {
  border-color: rgba(180, 35, 24, 0.24);
  background: #fff7f6;
}

.exam-card {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 14px;
  align-items: start;
  padding: 16px;
  border: 1px solid #dcecff;
  border-radius: 16px;
  background: linear-gradient(135deg, #f4fbff, #f5f0ff);
}

.exam-card span {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: var(--blue-dark);
  background: white;
  border-radius: 12px;
  font-weight: 900;
}

.login-modal {
  width: min(520px, calc(100% - 28px));
  border: 0;
  border-radius: 24px;
  padding: 0;
  background: transparent;
}

.login-modal::backdrop {
  background: rgba(17, 24, 39, 0.34);
  backdrop-filter: blur(6px);
}

.login-modal form {
  position: relative;
  display: grid;
  gap: 16px;
  padding: 28px;
}

#loginStep,
#otpStep,
.course-code-form {
  display: grid;
  gap: 16px;
}

#loginStep[hidden],
#otpStep[hidden] {
  display: none;
}

.course-code-form {
  width: min(520px, 100%);
}

.form-message {
  min-height: 24px;
  margin: 0;
  color: #b42318;
  font-weight: 800;
  line-height: 1.7;
}

.form-message.success {
  color: #087c61;
}

.temp-login-note {
  margin: 0;
  padding: 10px 12px;
  color: var(--blue-dark);
  background: #e9f7ff;
  border: 1px solid #d7effb;
  border-radius: 12px;
  font-size: 0.9rem;
}

.close-button {
  position: absolute;
  top: 16px;
  left: 16px;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 0;
  color: var(--ink);
  background: #eef4fb;
  border-radius: 12px;
  font-size: 1.5rem;
  line-height: 1;
}

label {
  display: grid;
  gap: 8px;
  color: #344054;
  font-weight: 900;
}

input {
  width: 100%;
  border: 1px solid #d9e5f1;
  border-radius: 14px;
  padding: 14px 15px;
  color: var(--ink);
  background: white;
  outline: none;
}

input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(18, 166, 223, 0.12);
}

footer {
  display: flex;
  justify-content: center;
  gap: 10px;
  padding: 34px 16px;
  border-top: 1px solid var(--line);
}

@media (max-width: 980px) {
  .site-header {
    top: 10px;
    flex-wrap: wrap;
  }

  .brand,
  .header-actions {
    min-width: auto;
  }

  .top-menu {
    order: 3;
    width: 100%;
    overflow-x: auto;
    justify-content: flex-start;
    padding-top: 8px;
  }

  .hero,
  .exam-panel,
  .registration-steps,
  .auto-solve-section {
    grid-template-columns: 1fr;
  }

  .steps-copy {
    position: static;
  }

  .wide-step:nth-child(2),
  .wide-step:nth-child(3) {
    transform: none;
  }

  .hero-art {
    order: 2;
    justify-self: center;
  }

  .hero-copy {
    justify-self: stretch;
  }

  .steps-grid,
  .course-grid,
  .student-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .site-header {
    width: calc(100% - 24px);
    padding: 12px;
  }

  .brand span:last-child {
    display: none;
  }

  .login-link {
    padding: 11px 13px;
    font-size: 0.9rem;
  }

  .hero,
  .section,
  .student-shell,
  .registration-steps,
  .auto-solve-section {
    width: calc(100% - 24px);
    min-height: auto;
    padding: 54px 0;
  }

  .hero-art {
    width: 100%;
    min-height: 430px;
  }

  .core {
    width: 118px;
    height: 118px;
  }

  .core span {
    font-size: 1.1rem;
  }

  .core small {
    font-size: 0.72rem;
  }

  .float-card {
    min-width: 148px;
    padding: 11px;
    font-size: 0.84rem;
  }

  .hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-top: 34px;
  }

  .hero-stats strong {
    font-size: 1.2rem;
  }

  .solver-note {
    right: 22px;
    max-width: calc(100% - 44px);
    font-size: 0.78rem;
  }

  .answer-ring {
    right: 12%;
    bottom: 14%;
    width: 72px;
    height: 56px;
  }

  .answer-badge {
    right: 8%;
    bottom: 5%;
    font-size: 0.82rem;
  }

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

  .exam-set-grid {
    grid-template-columns: 1fr;
  }

  .steps-grid,
  .course-grid,
  .student-grid {
    grid-template-columns: 1fr;
  }

  .student-header,
  .wide-step,
  footer {
    display: grid;
  }

  .wide-step {
    grid-template-columns: 52px 1fr;
    gap: 16px;
    padding: 22px;
  }

  .wide-step strong {
    grid-column: 1 / -1;
  }
}

@keyframes rotateHero {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes corePulse {
  0%,
  100% {
    transform: translate(-50%, -50%) scale(1);
    box-shadow: 0 22px 70px rgba(16, 24, 40, 0.12);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.05);
    box-shadow: 0 30px 90px rgba(18, 166, 223, 0.2);
  }
}

@keyframes floatCard {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-14px);
  }
}

@keyframes sparkle {
  0%,
  100% {
    transform: scale(0.7);
    opacity: 0.35;
  }
  50% {
    transform: scale(1.25);
    opacity: 1;
  }
}

@keyframes driftGlow {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(28px, -18px, 0) scale(1.16);
  }
}

@keyframes solveNote {
  0%,
  18%,
  100% {
    opacity: 0;
    transform: translateY(12px);
  }
  28%,
  54% {
    opacity: 1;
    transform: translateY(0);
  }
  64% {
    opacity: 0;
    transform: translateY(-8px);
  }
}

@keyframes answerPop {
  0%,
  48%,
  100% {
    opacity: 0;
    transform: scale(0.7);
  }
  58%,
  82% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes answerBadge {
  0%,
  54%,
  100% {
    opacity: 0;
    transform: translateY(14px);
  }
  64%,
  86% {
    opacity: 1;
    transform: translateY(0);
  }
}