/* =========================================================
   LANDING PAGE STYLES — Nekh's Language Blueprint hub
   Scope: index.html only.
   Font stack lifted verbatim from Language-learning-app/style.css
   so the hub and the app feel like one product.
   ========================================================= */

:root {
  --font-ui: system-ui, -apple-system, "Segoe UI", Roboto, Arial,
    "Hiragino Sans", "Hiragino Kaku Gothic ProN",
    "Yu Gothic", "Meiryo",
    "Noto Sans JP", "Noto Sans CJK JP",
    sans-serif;

  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New",
    "Noto Sans Mono CJK JP", "Noto Sans JP",
    "Yu Gothic", "Meiryo",
    monospace;

  --brand-blue: #0b4f8f;
  --brand-deep: #06335c;
  --ink: #ffffff;
  --ink-soft: rgba(255, 255, 255, 0.85);
  --ink-faint: rgba(255, 255, 255, 0.6);
  --card-bg: rgba(255, 255, 255, 0.07);
  --card-border: rgba(255, 255, 255, 0.18);
  --accent: #fbbf24;
}

/* Reset just what the landing page needs */
.landing-body * { box-sizing: border-box; }
.landing-body { margin: 0; }

.landing-body {
  font-family: var(--font-ui);
  color: var(--ink);
  line-height: 1.55;
}

/* Top utility bar (existing-user shortcut to /login) */
.top-utility {
  display: flex;
  justify-content: flex-end;
  padding: 12px 20px 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
}

.top-utility a {
  color: var(--ink-faint);
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 6px 14px;
  border-radius: 999px;
  transition: color 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}

.top-utility a:hover {
  color: var(--ink);
  border-color: rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.06);
}

/* Layout shell */
.landing {
  width: min(1080px, 92vw);
  margin: 0 auto;
  padding: 24px 0 56px;
}

.landing section {
  padding: 64px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.landing section:last-of-type {
  border-bottom: none;
}

/* ========== HERO ========== */
.hero {
  text-align: center;
  padding-top: 56px;
}

.hero-brand {
  font-family: var(--font-ui);
  font-weight: 900;
  letter-spacing: 0.06em;
  font-size: clamp(2.4rem, 6.5vw, 4.4rem);
  line-height: 1.02;
  margin: 0 0 18px;
}

.hero-tagline {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 2vw, 1.2rem);
  max-width: 640px;
  margin: 0 auto 32px;
  color: var(--ink-soft);
  letter-spacing: 0.02em;
}

.hero-form {
  display: flex;
  gap: 10px;
  width: min(520px, 100%);
  margin: 0 auto;
  flex-wrap: wrap;
  justify-content: center;
}

.hero-form input[type="email"] {
  flex: 1 1 240px;
  min-width: 0;
  padding: 14px 18px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.08);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.hero-form input[type="email"]::placeholder {
  color: rgba(255, 255, 255, 0.45);
}

.hero-form input[type="email"]:focus {
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.14);
}

.hero-form button {
  padding: 14px 24px;
  border-radius: 999px;
  border: none;
  font-family: var(--font-ui);
  font-weight: 800;
  letter-spacing: 0.06em;
  font-size: 1rem;
  background: var(--ink);
  color: var(--brand-blue);
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  white-space: nowrap;
}

.hero-form button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.25);
}

.hero-form-note {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
}

/* ========== Section headings ========== */
.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 12px;
}

.section-title {
  font-family: var(--font-ui);
  font-weight: 900;
  letter-spacing: 0.04em;
  font-size: clamp(1.8rem, 3.2vw, 2.4rem);
  margin: 0 0 24px;
}

/* ========== What is this ========== */
.what-prose {
  max-width: 720px;
  font-size: 1.05rem;
  color: var(--ink-soft);
}

.what-prose p {
  margin: 0 0 18px;
}

.what-prose p:last-child {
  margin-bottom: 0;
}

/* ========== Products row ========== */
.products-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-top: 24px;
}

.product-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  text-align: left;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.product-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, 0.32);
  background: rgba(255, 255, 255, 0.1);
}

.product-card-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 10px;
}

.product-card-title {
  font-family: var(--font-ui);
  font-weight: 800;
  letter-spacing: 0.02em;
  font-size: 1.25rem;
  margin: 0 0 12px;
}

.product-card-body {
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin: 0 0 22px;
  flex: 1;
  line-height: 1.5;
}

.product-card-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  align-self: flex-start;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--brand-blue);
  font-family: var(--font-ui);
  font-weight: 800;
  letter-spacing: 0.04em;
  font-size: 0.9rem;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.product-card-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.25);
}

/* ========== YouTube section ========== */
.youtube-wrap {
  display: flex;
  flex-direction: column;
  gap: 18px;
  align-items: stretch;
  max-width: 880px;
}

.youtube-frame {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
  border-radius: 16px;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--card-border);
}

.youtube-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.youtube-link {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  align-self: flex-start;
  padding-bottom: 2px;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.youtube-link:hover {
  color: var(--ink);
  border-color: var(--ink);
}

/* ========== About ========== */
.about-prose {
  max-width: 680px;
  font-size: 1.05rem;
  color: var(--ink-soft);
}

.about-prose p {
  margin: 0;
}

/* ========== Footer ========== */
.landing-footer {
  margin-top: 48px;
  padding: 24px 0 8px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  letter-spacing: 0.06em;
}

/* ========== Mobile ========== */
@media (max-width: 720px) {
  .landing { width: min(540px, 92vw); padding: 16px 0 40px; }
  .landing section { padding: 48px 0; }
  .hero { padding-top: 32px; }
  .products-grid { grid-template-columns: 1fr; gap: 16px; }
  .product-card { padding: 22px 20px; }
  .top-utility { padding: 10px 16px 0; }
}

@media (min-width: 721px) and (max-width: 1000px) {
  .products-grid { grid-template-columns: repeat(2, 1fr); }
}