/* =========================================================
   プログラミングステーション 共通スタイル（ライトテーマ）
   ========================================================= */
:root {
  --color-bg: #f6f7fb;
  --color-bg-soft: #eef0f8;
  --color-surface: #ffffff;
  --color-border: #dfe3f0;
  --color-text: #1f2333;
  --color-text-muted: #5b6178;
  --color-primary: #4a5fd6;
  --color-primary-dark: #33409e;
  --color-accent: #0f9d8f;
  --color-warn: #b3720d;
  --color-danger: #d1435b;
  --color-success: #1f9d55;
  --radius: 14px;
  --max-width: 1080px;
  --font-main: "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  --font-mono: "Cascadia Code", "Consolas", "SFMono-Regular", Menlo, monospace;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-main);
  background: radial-gradient(circle at top, #ffffff 0%, #eef1fa 60%);
  color: var(--color-text);
  line-height: 1.8;
  min-height: 100vh;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img, svg {
  max-width: 100%;
}

/* ---------- ヘッダー ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 1px 0 rgba(15, 23, 42, 0.03);
}

.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-text);
}

.brand__logo {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.brand:hover {
  text-decoration: none;
}

.header-nav a {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  margin-left: 18px;
}

.header-nav a:hover {
  color: var(--color-primary);
}

/* ---------- レイアウト ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.hero {
  text-align: center;
  padding: 64px 24px 40px;
}

.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin-bottom: 12px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p {
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto;
  font-size: 1.02rem;
}

/* ---------- 言語カードグリッド ---------- */
.lang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 20px;
  margin-top: 32px;
}

.lang-card {
  display: block;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px 20px;
  transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
  text-decoration: none;
  color: var(--color-text);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05);
}

.lang-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-primary);
  box-shadow: 0 10px 30px rgba(74, 95, 214, 0.16);
  text-decoration: none;
}

.lang-card__icon {
  font-size: 2rem;
  margin-bottom: 12px;
  display: block;
}

.lang-card__title {
  font-weight: 700;
  font-size: 1.08rem;
  margin-bottom: 6px;
}

.lang-card__desc {
  color: var(--color-text-muted);
  font-size: 0.88rem;
}

/* ---------- セクション共通 ---------- */
.page-title {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 8px;
}

.page-title__icon {
  font-size: 2.4rem;
}

.page-lead {
  color: var(--color-text-muted);
  margin-bottom: 40px;
  font-size: 1.02rem;
}

section.block {
  margin-bottom: 56px;
}

section.block h2 {
  font-size: 1.5rem;
  border-left: 5px solid var(--color-primary);
  padding-left: 14px;
  margin-bottom: 20px;
}

section.block h3 {
  font-size: 1.15rem;
  color: var(--color-primary);
  margin: 28px 0 10px;
}

.topic {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 22px 24px;
  margin-bottom: 20px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
}

.topic p {
  color: var(--color-text-muted);
}

.topic code.inline, p code, li code {
  background: rgba(74, 95, 214, 0.1);
  color: var(--color-accent);
  padding: 2px 6px;
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* ---------- コードブロック ---------- */
pre {
  background: #eef0f8;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 18px 20px;
  overflow-x: auto;
  margin: 14px 0;
}

pre code {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: #1f2333;
  white-space: pre;
  background: none;
  padding: 0;
}

.code-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: #ffffff;
  background: var(--color-accent);
  padding: 2px 10px;
  border-radius: 999px;
  margin-bottom: 6px;
  font-weight: 700;
}

/* ---------- 高速化Tips ---------- */
.perf-box {
  background: linear-gradient(135deg, rgba(15, 157, 143, 0.1), rgba(74, 95, 214, 0.08));
  border: 1px solid rgba(15, 157, 143, 0.35);
  border-radius: var(--radius);
  padding: 24px 26px;
}

.perf-box h2 {
  border-color: var(--color-accent);
}

.perf-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 14px;
}

.perf-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: rgba(255, 255, 255, 0.6);
  border-radius: 10px;
  padding: 12px 14px;
}

.perf-list li::before {
  content: "⚡";
  flex-shrink: 0;
}

/* ---------- クイズ ---------- */
.quiz-intro {
  color: var(--color-text-muted);
  margin-bottom: 18px;
}

.quiz-question {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin-bottom: 18px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
}

.quiz-question__title {
  font-weight: 700;
  margin-bottom: 12px;
}

.quiz-question__num {
  color: var(--color-primary);
  margin-right: 8px;
}

.quiz-options {
  display: grid;
  gap: 10px;
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  border-radius: 9px;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.quiz-option:hover {
  border-color: var(--color-primary);
  background: rgba(74, 95, 214, 0.04);
}

.quiz-option input {
  accent-color: var(--color-primary);
}

.quiz-question.is-correct {
  border-color: var(--color-success);
}

.quiz-question.is-wrong {
  border-color: var(--color-danger);
}

.quiz-option.correct-answer {
  border-color: var(--color-success);
  background: rgba(31, 157, 85, 0.12);
}

.quiz-option.wrong-answer {
  border-color: var(--color-danger);
  background: rgba(209, 67, 91, 0.12);
}

.quiz-explain {
  display: none;
  margin-top: 12px;
  padding: 12px 14px;
  background: rgba(74, 95, 214, 0.08);
  border-left: 3px solid var(--color-primary);
  border-radius: 6px;
  color: var(--color-text-muted);
  font-size: 0.92rem;
}

.quiz-question.is-graded .quiz-explain {
  display: block;
}

.quiz-actions {
  display: flex;
  gap: 14px;
  align-items: center;
  margin-top: 24px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.98rem;
  font-weight: 700;
  padding: 12px 26px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-primary-dark));
  color: #fff;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn.btn-secondary {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text);
}

.quiz-result {
  display: none;
  margin-top: 26px;
  padding: 22px 24px;
  border-radius: var(--radius);
  background: var(--color-bg-soft);
  border: 1px solid var(--color-border);
  text-align: center;
}

.quiz-result.is-visible {
  display: block;
}

.quiz-result__score {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-accent);
  margin-bottom: 6px;
}

.quiz-result__msg {
  color: var(--color-text-muted);
}

/* ---------- フッター ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

.back-link {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--color-text-muted);
}

.back-link:hover {
  color: var(--color-primary);
}

@media (max-width: 640px) {
  .hero { padding: 44px 16px 28px; }
  .container { padding: 28px 16px 60px; }
  section.block h2 { font-size: 1.3rem; }
}

/* ---------- 左右固定広告バナー ---------- */
:root {
  --banner-scale: clamp(0.3, calc(100vw / 2100px), 0.6667);
}
.side-banner {
  position: fixed;
  top: 96px;
  z-index: 10;
}
.side-banner.left {
  left: 16px;
  transform-origin: left top;
  transform: scale(var(--banner-scale));
}
.side-banner.right {
  right: 16px;
  transform-origin: right top;
  transform: scale(var(--banner-scale));
}