/* ===========================
   BitSummit Game Jam 2026
   Design: BitSummit Light Theme
   Base: White / Orange-Red Gradient
=========================== */

@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700;900&family=Oswald:wght@400;500;600;700&family=Bebas+Neue&display=swap");

:root {
  /* BitSummitカラーシステム */
  --color-bg: #f6f7fa;
  --color-bg-white: #ffffff;
  --color-bg-section: #f0f1f5;
  --color-text: #111111;
  --color-text-muted: rgba(17, 17, 17, 0.55);
  --color-text-light: rgba(17, 17, 17, 0.35);
  --color-border: #111111;
  --color-border-light: rgba(17, 17, 17, 0.12);

  /* オレンジ〜赤グラデーション */
  --color-orange: #f96a2e; /* rgb(249, 106, 46) — BitSummit公式オレンジ */
  --color-red: #e8272a; /* 赤 */
  --color-grad-start: #f96a2e;
  --color-grad-end: #e8272a;
  --grad-main: linear-gradient(
    135deg,
    var(--color-grad-start) 0%,
    var(--color-grad-end) 100%
  );
  --grad-text: linear-gradient(135deg, #f96a2e 0%, #e8272a 100%);

  --font-display: "Bebas Neue", "Oswald", sans-serif;
  --font-heading: "Oswald", "Noto Sans JP", sans-serif;
  --font-body: "Noto Sans JP", sans-serif;
  --max-width: 1080px;
  --section-pad: 96px 24px;
}

/* ===========================
   リセット・ベース
=========================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  color: inherit;
  text-decoration: none;
}

/* ===========================
   パスワードロック（index.html）
=========================== */
#lock-screen {
  position: fixed;
  inset: 0;
  z-index: 10000;
  background: var(--color-bg);
  overflow-y: auto;
}

#lock-screen[hidden] {
  display: none !important;
}

.lock-screen-inner {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--section-pad);
}

.lock-label {
  display: block;
  margin-top: 16px;
  margin-bottom: 8px;
}

.lock-input {
  max-width: 320px;
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--color-border-light);
  border-radius: 6px;
  font: inherit;
}

.lock-submit {
  margin-top: 12px;
  padding: 8px 16px;
  border-radius: 999px;
  border: none;
  background: #111827;
  color: #fff;
  cursor: pointer;
  font: inherit;
}

.lock-submit:hover {
  opacity: 0.92;
}

.lock-msg {
  margin-top: 8px;
  color: #e11d48;
  min-height: 1.5em;
}

.main-content[hidden] {
  display: none !important;
}

/* ===========================
   ナビゲーション
=========================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--color-bg-white);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  padding: 0 24px;
}

.nav-logo-img {
  height: 36px;
  width: auto;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 28px;
}

.nav-links a {
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--color-red);
}

/* ===========================
   ヒーローセクション
=========================== */
.hero {
  position: relative;
  padding-top: 60px;
  background: var(--color-bg-white);
  border-bottom: 1px solid var(--color-border);
  overflow: hidden;
}

/* ヒーロー上部：グラデーション帯 */
.hero-band {
  background: var(--grad-main);
  padding: 6px 0;
  text-align: center;
}

.hero-band-text {
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: #ffffff;
}

.hero-main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 64px 24px 56px;
  gap: 48px;
}

.hero-left {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.hero-logo-wrap {
  display: block;
}

.hero-logo {
  max-width: 360px;
  width: 100%;
}

.hero-tagline {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.tagline-en {
  font-family: var(--font-heading);
  font-size: clamp(22px, 3.5vw, 38px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: 0.02em;
  background: var(--grad-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline-ja {
  font-size: clamp(14px, 2vw, 18px);
  font-weight: 700;
  color: var(--color-text);
}

.hero-sub {
  font-size: 14px;
  color: var(--color-text-muted);
  font-style: italic;
  border-left: 3px solid var(--color-orange);
  padding-left: 12px;
}

.hero-badge {
  display: inline-block;
}

.badge-text {
  display: inline-block;
  padding: 6px 18px;
  background: #fff0ee;
  border: 1.5px solid var(--color-red);
  border-radius: 2px;
  color: var(--color-red);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.hero-right {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-date-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  padding: 28px 32px;
}

.date-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border-light);
}

.date-row:last-child {
  border-bottom: none;
}

.date-label {
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--color-orange);
  min-width: 90px;
}

.date-value {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--color-text);
}

/* ===========================
   セクション共通
=========================== */
.section {
  padding: var(--section-pad);
  background: var(--color-bg);
}

.section-white {
  background: var(--color-bg-white);
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

/* セクションヘッダー */
.section-header {
  margin-bottom: 52px;
}

.section-label {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--color-orange);
  margin-bottom: 10px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(28px, 4vw, 32px);
  font-weight: 700;
  line-height: 1.15;
  color: var(--color-text);
  position: relative;
  padding-bottom: 20px;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--grad-main);
  border-radius: 2px;
}

/* ===========================
   ABOUTセクション
=========================== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: start;
  margin-bottom: 40px;
}

.about-text p {
  margin-bottom: 18px;
  color: rgba(17, 17, 17, 0.8);
  line-height: 1.9;
  font-size: 15px;
}

/* .about-link{
  color: var(--color-orange);
} */

a:hover {
  color: var(--color-orange);
  transition: color 0.2s;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.stat-item {
  text-align: center;
  padding: 24px 12px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  border-top: 3px solid var(--color-orange);
}

.stat-num {
  font-family: var(--font-display);
  font-size: 48px;
  line-height: 1;
  background: var(--grad-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 12px;
  color: var(--color-text-muted);
  font-weight: 500;
}

.about-goal {
  display: flex;
  gap: 20px;
  padding: 28px;
  background: #fff7f4;
  border-left: 4px solid var(--color-orange);
  border-radius: 0 4px 4px 0;
}

.goal-icon {
  font-size: 28px;
  flex-shrink: 0;
}

.goal-text strong {
  display: block;
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-orange);
}

.goal-text p {
  color: rgba(17, 17, 17, 0.8);
  font-size: 14px;
  line-height: 1.8;
}

/* ===========================
   THEMEセクション
=========================== */
.theme-hero {
  background: var(--grad-main);
  padding: 56px 24px;
  text-align: center;
  margin-bottom: 40px;
}

.theme-hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.theme-eyebrow {
  font-family: var(--font-heading);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 12px;
}

.theme-hero-en {
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 96px);
  line-height: 0.95;
  color: #ffffff;
  letter-spacing: 0.02em;
  margin-bottom: 16px;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

.theme-hero-ja {
  font-size: clamp(16px, 2.5vw, 22px);
  font-weight: 700;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 12px;
}

.theme-hero-quote {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.75);
  font-style: italic;
}

.theme-context {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.theme-context-label {
  font-family: var(--font-heading);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  margin-bottom: 20px;
  text-align: center;
}

.theme-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 40px;
}

.theme-split-item {
  padding: 32px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  border-top: 3px solid var(--color-orange);
}

.theme-split-tag {
  font-family: var(--font-heading);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-orange);
  margin-bottom: 12px;
}

.theme-split-word {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: 10px;
}

.theme-split-desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.theme-bitsummit-note {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 24px 32px;
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
}

.bitsummit-note-label {
  font-family: var(--font-heading);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  flex-shrink: 0;
  min-width: 120px;
}

.bitsummit-note-content strong {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  display: block;
  margin-bottom: 4px;
}

.bitsummit-note-content span {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* ===========================
   SCHEDULEセクション
=========================== */
.schedule-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-bottom: 48px;
}

.phase {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 0;
  border-bottom: 1px solid var(--color-border-light);
}

.phase:first-child {
  border-top: 1px solid var(--color-border-light);
}

.phase-num-col {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 32px 0;
  border-right: 1px solid var(--color-border-light);
}

.phase-num {
  font-family: var(--font-display);
  font-size: 40px;
  line-height: 1;
  color: var(--color-orange);
  opacity: 0.4;
}

.phase-content {
  padding: 32px 0 32px 32px;
}

.phase-title {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-text);
}

.phase-status {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 2px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 20px;
}

.phase-status.closed {
  background: #fff0ee;
  border: 1px solid var(--color-red);
  color: var(--color-red);
}

.phase-tag {
  display: inline-block;
  padding: 3px 12px;
  background: #fff7f4;
  border: 1px solid rgba(249, 106, 46, 0.3);
  border-radius: 2px;
  font-size: 11px;
  color: var(--color-orange);
  margin-bottom: 20px;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.phase-items {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.phase-item {
  display: flex;
  gap: 24px;
  align-items: baseline;
}

.phase-date {
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-orange);
  flex-shrink: 0;
  min-width: 110px;
}

.phase-desc {
  font-size: 14px;
  color: rgba(17, 17, 17, 0.75);
}

.phase-item.highlight .phase-date {
  color: var(--color-red);
}

.phase-item.highlight .phase-desc {
  color: var(--color-text);
  font-weight: 700;
}

/* 会場 */
.venue-block {
  margin-top: 8px;
}

.venue-label {
  font-family: var(--font-heading);
  font-size: 11px;
  letter-spacing: 0.25em;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.venue-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.venue-item {
  padding: 24px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  border-left: 3px solid var(--color-orange);
}

.venue-city {
  font-family: var(--font-display);
  font-size: 24px;
  letter-spacing: 0.1em;
  color: var(--color-orange);
  margin-bottom: 8px;
}

.venue-name {
  font-size: 14px;
  color: rgba(17, 17, 17, 0.75);
  line-height: 1.7;
}

/* ===========================
   CONNECTセクション
=========================== */
.connect-intro {
  color: rgba(17, 17, 17, 0.75);
  margin-bottom: 36px;
  font-size: 15px;
  max-width: 680px;
}

.connect-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.connect-item {
  padding: 32px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  border-top: 3px solid var(--color-orange);
  transition: box-shadow 0.2s;
}

.connect-item:hover {
  box-shadow: 0 4px 20px rgba(249, 106, 46, 0.15);
}

.connect-name {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-text);
}

.connect-sub {
  font-size: 12px;
  color: var(--color-orange);
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: 0.05em;
}

.connect-desc {
  font-size: 14px;
  color: rgba(17, 17, 17, 0.65);
  line-height: 1.8;
}

/* ===========================
   SPONSORSセクション
=========================== */
.sponsor-block {
  margin-bottom: 48px;
}

.sponsor-category {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--font-heading);
  font-size: 12px;
  letter-spacing: 0.25em;
  color: var(--color-text-muted);
  margin-bottom: 20px;
  text-transform: uppercase;
}

.sponsor-category::before {
  content: "";
  display: block;
  width: 24px;
  height: 2px;
  background: var(--grad-main);
  flex-shrink: 0;
}

.sponsor-category::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--color-border-light);
}

.sponsor-logos {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: stretch;
}
@media (max-width: 768px) {
  .sponsor-logos {
    justify-content: center;
  }
}

/* ===== Silver Sponsor ===== */
.sponsor-logos-silver {
  justify-content: flex-start;
}
@media (max-width: 768px) {
  .sponsor-logos-silver {
    justify-content: center;
  }
  .sponsor-logos-bronze {
    justify-content: center !important;
  }
}

.sponsor-logo-item--silver {
  background: var(--color-bg-white);
  /*border: 1px solid var(--color-border-light);*/
  border: 1px solid #1111111f;
  border-radius: 8px;
  padding: 32px 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 320px;
  height: 160px;
  flex: 0 0 320px;
  transition:
    border-color 0.2s,
    box-shadow 0.2s;
}

.sponsor-logo-item--silver:hover {
  border-color: var(--color-orange);
  box-shadow: 0 4px 16px rgba(249, 106, 46, 0.12);
}

/* Silver共通ロゴ */
.sponsor-logo--silver {
  max-height: 80px;
  max-width: 240px;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* CyberAgent：横長ロゴ → カード幅いっぱいに広げる */
.sponsor-logo-item--silver .sponsor-logo--cyberagent {
  max-width: 280px !important;
  max-height: 140px !important;
  width: 280px !important;
  height: auto !important;
  object-fit: contain;
}
/* CyberAgentカードのpaddingを最小化 */
.sponsor-logo-item--silver:has(.sponsor-logo--cyberagent) {
  padding: 10px 16px;
}

/* G-SMASH：横長ロゴ */
.sponsor-logo--gsmash {
  max-width: 240px;
  max-height: 70px;
}

/* ===== Bronze Sponsor ===== */
.sponsor-logos-bronze {
  justify-content: left;
}

.sponsor-logo-item--bronze {
  background: var(--color-bg-white);
  /*border: 1px solid var(--color-border-light);*/
  border: 1px solid #1111111f;
  border-radius: 8px;
  padding: 32px 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 320px;
  height: 160px;
  flex: 0 0 320px;
  transition:
    border-color 0.2s,
    box-shadow 0.2s;
}

.sponsor-logo-item--bronze:hover {
  border-color: var(--color-orange);
  box-shadow: 0 4px 16px rgba(249, 106, 46, 0.12);
}

.sponsor-logo--bronze {
  max-height: 80px;
  max-width: 240px;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* ===== 階層ラベル（Silver / Bronze） ===== */
.sponsor-tier {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 8px;
  font-size: 10px;
  font-family: var(--font-heading);
  letter-spacing: 0.15em;
  border-radius: 2px;
  background: linear-gradient(135deg, #c0c0c0, #e8e8e8);
  color: #555;
  vertical-align: middle;
  text-transform: uppercase;
}

.sponsor-tier--bronze {
  background: linear-gradient(135deg, #cd7f32, #e8a96a);
  color: #fff;
}

/* ===== 運営協力・会場協力 ===== */
.sponsor-logos-sub .sponsor-logo-item {
  background: var(--color-bg-white);
  /*border: 1px solid var(--color-border-light);*/
  border: 1px solid #1111111f;
  border-radius: 8px;
  padding: 28px 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 180px;
  height: 130px;
  flex: 1;
  max-width: 260px;
  transition:
    border-color 0.2s,
    box-shadow 0.2s;
}

.sponsor-logos-sub .sponsor-logo-item:hover {
  border-color: var(--color-orange);
  box-shadow: 0 4px 16px rgba(249, 106, 46, 0.12);
}

/* 共通ロゴ画像デフォルト */
.sponsor-logo {
  max-height: 70px;
  max-width: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* 運営協力・会場協力 ロゴ画像 */
.sponsor-logos-sub .sponsor-logo {
  max-height: 70px;
  max-width: 220px;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* KONAMI：横長ロゴ */
.sponsor-logos-sub .sponsor-logo--konami {
  max-height: 60px !important;
  max-width: 220px !important;
  width: auto;
  height: auto;
}

@media (max-width: 950px) {
  .sponsor-logos-sub .sponsor-logo--konami {
    max-width: 125px !important;
  }
}

/* Skeleton Crew Studio */
.sponsor-logos-sub .sponsor-logo--skeleton {
  max-height: 80px !important;
  max-width: 220px !important;
  width: auto;
  height: auto;
}

/* ホテルアンテルーム京都：正方形ロゴ */
.sponsor-logos-sub .sponsor-logo--anteroom {
  max-height: 90px !important;
  max-width: 90px !important;
  width: auto;
  height: auto;
}

/* ===========================
   ORGANIZERSセクション
=========================== */
.org-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 32px;
}

.org-block {
  padding: 28px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  border-top: 3px solid var(--color-orange);
}

.org-role {
  font-family: var(--font-heading);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-orange);
  margin-bottom: 12px;
}

.org-names p {
  font-size: 14px;
  color: rgba(17, 17, 17, 0.8);
  margin-bottom: 6px;
  line-height: 1.6;
}

.committee-section {
  padding: 36px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
}

.committee-title {
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 28px;
  color: var(--color-text);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border-light);
}

.committee-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}

.committee-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px;
  background: var(--color-bg);
  border-radius: 4px;
  border-left: 2px solid var(--color-orange);
}

.committee-name {
  font-weight: 700;
  font-size: 14px;
  color: var(--color-text);
}

.committee-role {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* ===========================
   フッター
=========================== */
.footer {
  background: var(--color-text);
  padding: 56px 24px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  text-align: center;
}

.footer-logo-img {
  height: 52px;
  width: auto;
  margin: 0 auto;
  filter: brightness(0) invert(1);
  opacity: 0.85;
}

.footer-info p {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.55);
  margin-bottom: 4px;
}

.footer-copy p {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.3);
  margin-top: 8px;
}

/* ===========================
   アニメーション
=========================== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s ease,
    transform 0.5s ease;
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===========================
   レスポンシブ
=========================== */
@media (max-width: 768px) {
  :root {
    --section-pad: 64px 20px;
  }

  .nav-links {
    display: none;
  }

  .hero-main {
    grid-template-columns: 1fr;
    padding: 40px 20px 48px;
    gap: 32px;
  }

  .hero-logo {
    max-width: 280px;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }

  .theme-split {
    grid-template-columns: 1fr;
  }

  .theme-bitsummit-note {
    flex-direction: column;
    gap: 12px;
  }

  .phase {
    grid-template-columns: 60px 1fr;
  }

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

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

  .sponsor-logos-main .sponsor-logo-item,
  .sponsor-logos-sub .sponsor-logo-item {
    min-width: 130px;
    padding: 14px 16px;
  }

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

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

@media (max-width: 480px) {
  .about-stats {
    grid-template-columns: 1fr;
  }

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

  .phase-num-col {
    justify-content: flex-start;
    padding: 24px 0 8px;
    border-right: none;
    border-bottom: 1px solid var(--color-border-light);
  }

  .phase-content {
    padding: 16px 0 24px;
  }
}