* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #0b0f1c;
  --blue-dark: #0f2060;
  --blue-mid: #1a3a8f;
  --blue-bright: #2563eb;
  --blue-border: #1e40af;
  --blue-light: #3b82f6;
  --accent: #60a5fa;
  --white: #ffffff;
  --gray: #94a3b8;
  --light: #cbd5e1;
}

html, body {
  font-family: 'Noto Sans JP', sans-serif;
  background: #151929;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 80px;
  padding: 20px;
  min-height: 100vh;
}

/* ===== SLIDE BASE ===== */
.slide {
  width: 1280px;
  height: 720px;
  background: var(--bg);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
  display: flex;
}

.slide-num {
  position: absolute;
  top: 22px;
  right: 34px;
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 2px;
  z-index: 10;
}

/* ===== COMMONS ===== */
.section-title {
  font-size: 38px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 34px;
  flex-shrink: 0;
}

.blue-card {
  background: var(--blue-mid);
  border-radius: 10px;
  padding: 20px 22px;
}

.border-card {
  border: 1px solid var(--blue-border);
  border-radius: 10px;
  padding: 16px 20px;
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 7px;
}

.card-desc {
  font-size: 15px;
  color: rgba(255,255,255,0.75);
  line-height: 1.65;
}

.border-card .card-desc {
  color: var(--gray);
}

.dot-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.dot-list li {
  font-size: 13px;
  color: var(--gray);
  display: flex;
  gap: 7px;
  align-items: flex-start;
  line-height: 1.5;
}

.dot-list li::before {
  content: '•';
  color: var(--blue-light);
  flex-shrink: 0;
}

/* 이미지 placeholder */
.img-box {
  background: #182033;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  flex-shrink: 0;
}

.img-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ============================================================
    S1: TITLE  (이미지560 + 텍스트720)
============================================================ */
#s1 {
  display: grid;
  grid-template-columns: 560px 720px;
}

#s1 .s1-img {
  width: 560px;
  height: 720px;
}

#s1 .s1-right {
  background: var(--bg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0 66px;
}

#s1 .s1-label {
  font-size: 19px;
  color: var(--light);
  font-weight: 300;
  margin-bottom: 20px;
}

#s1 .s1-h1 {
  font-size: 58px;
  font-weight: 700;
  color: var(--white);
  line-height: 1.1;
  margin-bottom: 8px;
}

#s1 .s1-h2 {
  font-size: 58px;
  font-weight: 700;
  color: var(--white);
  line-height: 1.1;
  margin-bottom: 26px;
}

#s1 .s1-sub {
  font-size: 13px;
  color: var(--gray);
  line-height: 1.7;
}

/* ============================================================
    S2: 目次
============================================================ */
#s2 {
  flex-direction: column;
  padding: 56px 90px 50px;
  justify-content: center;
}

#s2 .toc-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

#s2 .toc-item {
  padding: 24px 0;
  border-top: 1px solid var(--blue-bright);
}

#s2 .toc-item:nth-child(odd) {
  padding-right: 80px;
  border-right: 1px solid #1e293b;
}

#s2 .toc-item:nth-child(even) {
  padding-left: 80px;
}

#s2 .toc-num {
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 1px;
  margin-bottom: 7px;
}

#s2 .toc-h {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 5px;
}

#s2 .toc-s {
  font-size: 13px;
  color: var(--gray);
}

/* ============================================================
    S3: 開発目的  (배너220 + 내용)
============================================================ */
#s3 {
  flex-direction: column;
}

#s3 .s3-banner {
  width: 1280px;
  height: 220px;
}

#s3 .s3-body {
  flex: 1;
  padding: 32px 90px 24px;
  display: flex;
  flex-direction: column;
}

#s3 .s3-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 44px;
}

.p-rows {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.p-row {
  display: flex;
  align-items: stretch;
}

.p-icon-col {
  width: 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
}

.p-icon {
  width: 50px;
  height: 50px;
  background: var(--blue-mid);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  color: white;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

.p-line {
  width: 2px;
  flex: 1;
  background: var(--blue-mid);
  margin-top: -2px;
}

.p-text {
  padding: 4px 0 50px 16px;
  flex: 1;
}

.p-label {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 4px;
}

.p-desc {
  font-size: 16px;
  color: var(--gray);
  line-height: 1.65;
}

/* ============================================================
    S4: システム概要
============================================================ */
#s4 {
  align-items: center;
  padding: 56px 90px;
  gap: 54px;
}

#s4 .s4-left {
  width: 460px;
  flex-shrink: 0;
}

#s4 .s4-right {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#s4 .s4-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 4px;
}

#s4 .s4-desc {
  font-size: 16px;
  color: var(--light);
  margin-bottom: 3px;
}

#s4 .s4-core {
  font-size: 16px;
  font-weight: 700;
  color: var(--light);
  margin-bottom: 14px;
}

#s4 hr {
  border: none;
  border-top: 1px solid #1e293b;
  margin: 12px 0;
}

#s4 .s4-users-h {
  font-size: 14px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 9px;
}

/* ============================================================
    S5: 主要機能
============================================================ */
#s5 {
  flex-direction: column;
  padding: 48px 90px;
}

#s5 .f-row1 {
  display: grid;
  grid-template-columns: repeat(4,1fr);
  gap: 13px;
  margin-bottom: 13px;
  flex: 1;
}

#s5 .f-row2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 13px;
  flex: 1;
}

#s5 .blue-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* ============================================================
    S6: 技術スタック
============================================================ */
#s6 {
  flex-direction: column;
  padding: 86px 90px;
}

#s6 .tech-grid {
  display: grid;
  grid-template-columns: repeat(4,1fr);
  gap: 16px;
  flex: 1;
}

#s6 .t-card {
  border: 1px solid var(--blue-border);
  border-radius: 12px;
  padding: 26px 22px;
}

#s6 .t-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 16px;
}

#s6 .dot-list li {
  font-size: 16px;
}

/* ============================================================
    S7: データベース設計
============================================================ */
#s7 {
  align-items: stretch;
  padding: 48px 90px;
  gap: 48px;
}

#s7 .db-left {
  width: 460px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

#s7 .db-t-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 12px;
}

#s7 .db-tlist {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

#s7 .db-tlist li {
  font-size: 15px;
  color: var(--light);
  display: flex;
  gap: 7px;
}

#s7 .db-tlist li::before {
  content: '•';
  color: var(--blue-light);
  flex-shrink: 0;
}

#s7 .db-tlist li strong {
  color: var(--white);
}

#s7 .db-right {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

#s7 .db-right img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}


/* ============================================================
    S8: ログイン
============================================================ */
#s8 {
  flex-direction: column;
  padding: 56px 90px;
  justify-content: center;
}

#s8 .lg-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  margin-top: 34px;
}

#s8 .lg-sec-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 16px;
}

#s8 .video-box {
  width: 100%;
  height: 315px;
  border-radius: 12px;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ============================================================
    S9: 映画リスト
============================================================ */
#s9 {
  flex-direction: column;
  padding: 44px 90px;
  align-items: center;
}

#s9 > .section-title {
  align-self: flex-start;
  margin-bottom: 0;
}

#s9 .s9-cards {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 16px;
  width: 100%;
}

#s9 .video-box {
  width: 100%;
  height: 315px;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 40px 0 32px;
}

/* ============================================================
    S10: AI推薦システム
============================================================ */
#s10 {
  flex-direction: column;
  padding: 48px 90px;
  align-items: center;
}

#s10 > .section-title {
  align-self: flex-start;
  margin-bottom: 30px;
}

#s10 .flow-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 680px;
}

#s10 .f-row {
  display: flex;
  align-items: center;
  width: 100%;
  height: 60px;
}

#s10 .f-row.right {
  flex-direction: row;
}

#s10 .f-num {
  width: 40px;
  height: 40px;
  background: var(--blue-mid);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 700;
  color: white;
  flex-shrink: 0;
  z-index: 2;
}

#s10 .f-text {
  flex: 1;
  padding: 0 22px;
}

#s10 .f-row.left .f-text {
  text-align: right;
}

#s10 .f-row.right .f-text {
  text-align: left;
}

#s10 .f-label {
  font-size: 14px;
  font-weight: 700;
  color: var(--white);
}

#s10 .f-desc {
  font-size: 12px;
  color: var(--gray);
}

#s10 .space {
  flex: 1;
  margin-right: 42px;
}

#s10 .f-vline {
  width: 2px;
  height: 32px;
  background: var(--blue-mid);
  margin: 0 auto;
}

/* ============================================================
    S11: AI技術的特徴
============================================================ */
#s11 {
  align-items: stretch;
  padding: 48px 90px;
  gap: 46px;
}

#s11 .s11-col {
  display: flex;
  flex-direction: column;
}

#s11 .s11-left {
  width: 510px;
  flex-shrink: 0;
}

#s11 .s11-cards {
  display: flex;
  flex-direction: column;
  gap: 13px;
  flex: 1;
}

#s11 .s11-card {
  background: var(--blue-mid);
  border-radius: 12px;
  padding: 18px 20px;
  display: flex;
  gap: 13px;
  align-items: flex-start;
}

#s11 .s11-right {
  flex: 1;
}

#s11 .video-box {
  width: 100%;
  height: 100%;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ============================================================
    S12: 掲示板
============================================================ */
#s12 {
  flex-direction: column;
  padding: 44px 90px;
  align-items: center;
}

#s12 > .section-title {
  align-self: flex-start;
  margin-bottom: 0;
}

#s12 .s12-cards {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 16px;
  width: 100%;
}

#s12 .video-box {
  width: 100%;
  height: 315px;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 40px 0 32px;
}

/* ============================================================
    S13: 管理者ダッシュボード
============================================================ */
#s13 {
  display: grid;
  grid-template-columns: 680px 1fr;
}

#s13 .s13-right {
  background: var(--bg);
  padding: 52px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 9px;
}

#s13 .s13-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 14px;
}

#s13 .s13-gap {
  height: 7px;
}

#s13 .video-box {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ============================================================
    S14: 技術的ハイライト
============================================================ */
#s14 {
  flex-direction: column;
  padding: 48px 90px;
}

#s14 .hi-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 13px;
  flex: 1;
}

#s14 .hi-card {
  border: 1px solid var(--blue-border);
  border-radius: 12px;
  padding: 22px 24px;
}

#s14 .hi-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 9px;
}

#s14 .hi-desc {
  font-size: 16px;
  color: var(--gray);
  line-height: 1.65;
}

/* ============================================================
    S15: 開発経験
============================================================ */
#s15 {
  flex-direction: column;
}

#s15 .s15-banner {
  width: 1280px;
  height: 208px;
}

#s15 .s15-body {
  flex: 1;
  padding: 36px 90px 32px;
}

#s15 .s15-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 72px;
}

#s15 .exp-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px 56px;
}

#s15 .exp-item {
  border-top: 2px solid var(--blue-bright);
  padding-top: 16px;
}

#s15 .exp-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 6px;
}

#s15 .exp-desc {
  font-size: 16px;
  color: var(--gray);
  line-height: 1.65;
}

/* ============================================================
    S16: ありがとうございました
============================================================ */
#s16 {
  flex-direction: column;
  justify-content: center;
  padding: 56px 90px;
}

#s16 .thanks-h {
  font-size: 72px;
  font-weight: 700;
  color: var(--white);
  line-height: 1;
  margin-bottom: 22px;
}

#s16 .thanks-name {
  font-size: 28px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 6px;
}

#s16 .thanks-sub {
  font-size: 16px;
  color: var(--gray);
  margin-bottom: 28px;
}

#s16 hr {
  border: none;
  border-top: 1px solid #1e293b;
  margin-bottom: 28px;
}

#s16 .thanks-grid {
  display: grid;
  grid-template-columns: repeat(4,1fr);
  gap: 14px;
}

#s16 .t-card {
  background: var(--blue-mid);
  border-radius: 10px;
  padding: 20px 18px;
}

#s16 .t-card-h {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 5px;
}

#s16 .t-card-s {
  font-size: 16px;
  color: rgba(255,255,255,0.62);
}

#s16 .thanks-git-btn {
  position: absolute;
  bottom: 58px;
  right: 90px;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--blue-bright);
  border: 1px solid var(--blue-border);
  border-radius: 10px;
  text-decoration: none;
  transition: background .2s, transform .2s;
}

#s16 .thanks-git-btn:hover {
  background: var(--blue-mid);
  transform: translateY(-2px);
  color: var(--white);
}

#s16 .thanks-git-btn img{
  width: 42px;
}

/* ===== NAV ===== */
.nav-bar {
  position: fixed;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 6px;
  z-index: 999;
}

.nav-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  border: none;
  cursor: pointer;
  transition: background .2s, transform .2s;
  outline: none;
}

.nav-dot:hover,
.nav-dot.on {
  background: var(--blue-bright);
  transform: scale(1.45);
}