:root {
  color-scheme: light;
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #eef3f8;
  --text: #172033;
  --muted: #647185;
  --line: #dbe3ee;
  --blue: #2563eb;
  --green: #0f9f6e;
  --ink: #111827;
  --red: #dc2626;
  --shadow: 0 18px 42px rgba(23, 32, 51, 0.12);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.84), rgba(245, 247, 251, 0.96)),
    url("data:image/svg+xml,%3Csvg width='1200' height='800' viewBox='0 0 1200 800' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' stroke='%23dbe3ee' stroke-width='1'%3E%3Cpath d='M0 120h1200M0 280h1200M0 440h1200M0 600h1200M160 0v800M360 0v800M620 0v800M900 0v800'/%3E%3C/g%3E%3C/svg%3E");
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  letter-spacing: 0;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 24px;
  align-items: end;
  min-height: 260px;
  padding: 32px 0;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 14px;
  color: var(--ink);
  font-size: clamp(44px, 8vw, 86px);
  line-height: 0.96;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0;
  color: var(--ink);
  font-size: 24px;
}

.subtitle {
  max-width: 560px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.6;
}

.session-card,
.login-panel,
.app-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: var(--shadow);
}

.session-card {
  display: grid;
  gap: 8px;
  padding: 20px;
}

.session-state {
  width: fit-content;
  border-radius: 999px;
  padding: 4px 10px;
  background: var(--surface-soft);
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.session-card.is-authenticated .session-state {
  background: #e8f7ef;
  color: var(--green);
}

.session-card strong {
  font-size: 18px;
}

.text-button {
  width: fit-content;
  border: 0;
  padding: 0;
  background: transparent;
  color: var(--blue);
  font-weight: 700;
}

.login-panel {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  margin-bottom: 24px;
  padding: 24px;
}

.login-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr)) auto;
  gap: 14px;
  align-items: end;
}

label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

input {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0 12px;
  background: var(--surface);
  color: var(--text);
}

input:focus {
  border-color: var(--blue);
  outline: 0;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.16);
}

.primary-button {
  min-height: 44px;
  border: 0;
  border-radius: var(--radius);
  padding: 0 20px;
  background: var(--ink);
  color: #fff;
  font-weight: 800;
}

.primary-button:disabled {
  cursor: progress;
  opacity: 0.65;
}

.form-error {
  grid-column: 1 / -1;
  min-height: 20px;
  margin: 0;
  color: var(--red);
  font-size: 13px;
  font-weight: 700;
}

.apps-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.app-card {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 32px;
  gap: 16px;
  align-items: center;
  min-height: 150px;
  padding: 24px;
  color: inherit;
  text-decoration: none;
  transition: transform 0.16s ease, border-color 0.16s ease;
}

.app-card:hover {
  border-color: #aebbd0;
  transform: translateY(-2px);
}

.app-mark {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  color: #fff;
  font-size: 22px;
  font-weight: 900;
}

.flashcards .app-mark {
  background: var(--blue);
}

.planning .app-mark {
  background: var(--green);
}

.app-card strong,
.app-card small {
  display: block;
}

.app-card strong {
  margin-bottom: 6px;
  color: var(--ink);
  font-size: 24px;
}

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

.arrow {
  color: var(--muted);
  font-size: 24px;
  font-weight: 800;
  text-align: right;
}

@media (max-width: 760px) {
  .shell {
    width: min(100% - 24px, 560px);
    padding: 24px 0;
  }

  .hero,
  .login-panel,
  .apps-grid,
  .login-form {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding: 16px 0;
  }

  .app-card {
    min-height: 124px;
  }
}