/* ========================================
   MOBAGE 20th ANNIVERSARY
   ======================================== */



.container {
  display: flex;
  justify-content: center; /* 水平方向の中央 */
  align-items: center;     /* 垂直方向の中央 */
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family:
    "Noto Sans JP",
    "Yu Gothic",
    "Hiragino Kaku Gothic ProN",
    Meiryo,
    sans-serif;

  background: #080b16;
  color: #fff;
  line-height: 1.8;
}

/* ========================================
   HEADER
   ======================================== */

.header {
  position: fixed;
  z-index: 100;
  top: 0;
  left: 0;
  width: 100%;
  height: 72px;

  background: rgba(5, 8, 18, 0.9);
  border-bottom: 1px solid rgba(255, 215, 120, 0.2);

  backdrop-filter: blur(12px);
}

.header-inner {
  width: min(1200px, calc(100% - 40px));
  height: 50%;
  margin: auto;

  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 15px;
}

.logo-main {
  font-size: 20px;
  font-weight: 900;
  letter-spacing: -1px;
}

.logo-sub {
  color: #e6bd65;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
}

.nav {
  display: flex;
  gap: 30px;
}

.nav a {
  color: #ddd;
  text-decoration: none;
  font-size: 13px;
  transition: 0.3s;
}

.nav a:hover {
  color: #f1cb73;
}


/* ========================================
   HERO
   ======================================== */

.hero {
  min-height: 30vh;
  position: relative;
  overflow: hidden;

  display: flex;
  align-items: center;
  justify-content: center;

  text-align: center;

  background:
    radial-gradient(
      circle at center,
      #25294a 0%,
      #11152b 38%,
      #070a15 75%
    );
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;

  background-image:
    linear-gradient(
      rgba(255,255,255,0.025) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      rgba(255,255,255,0.025) 1px,
      transparent 1px
    );

  background-size: 60px 60px;
}

.hero-glow {
  position: absolute;

  width: 650px;
  height: 650px;

  border-radius: 50%;

  background: rgba(216, 171, 68, 0.13);

  filter: blur(80px);
}

.hero-content {
  position: relative;
  z-index: 2;

  padding-top: 50px;
}

.anniversary-small {
  color: #e7c674;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 5px;
}

.twenty {
  margin: 5px 0 0;

  display: flex;
  justify-content: center;
  align-items: center;

  line-height: 0.85;
}

.number {
  font-family: Georgia, serif;
  font-size: clamp(180px, 27vw, 390px);
  font-weight: 900;

  background:
    linear-gradient(
      180deg,
      #fff4bf 0%,
      #e9c76c 30%,
      #a76c1b 65%,
      #f2d47e 100%
    );

  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;

  filter:
    drop-shadow(0 0 20px rgba(231, 191, 89, 0.3));
}

.zero {
  margin-left: -15px;
}

.hero h1 {
  margin-top: 20px;

  font-size: clamp(32px, 5vw, 62px);
  font-weight: 900;

  letter-spacing: 5px;
}

.hero-message {
  margin-top: 18px;

  color: #d2d4df;
  font-size: 15px;
}

.hero-line {
  width: 190px;
  height:5px;

  margin: 28px auto 15px;

  background: #d9b75e;
}

.since {
  color: #d9b75e;

  font-family: Georgia, serif;
  font-size: 16px;
  letter-spacing: 5px;
}


/* ========================================
   DECORATIONS
   ======================================== */

.floating-star {
  position: absolute;
  color: #f2d37b;
  font-size: 35px;
  opacity: 0.7;
  animation: float 4s ease-in-out infinite;
}

.star1 {
  top: 25%;
  left: 15%;
}

.star2 {
  top: 35%;
  right: 14%;
  animation-delay: 1s;
}

.star3 {
  bottom: 20%;
  left: 25%;
  animation-delay: 2s;
}

.star4 {
  bottom: 28%;
  right: 25%;
  animation-delay: 3s;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }

  50% {
    transform: translateY(-15px) rotate(10deg);
  }
}


/* ========================================
   COMMON SECTION
   ======================================== */

.section {
  width: min(1100px, calc(100% - 40px));
  margin: auto;
  padding: 130px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 65px;
}

.section-title span {
  color: #d8b65e;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 5px;
}

.section-title h2 {
  margin-top: 8px;
  font-size: 34px;
  letter-spacing: 3px;
}


/* ========================================
   ABOUT
   ======================================== */

.about {
  background: #0a0e1c;
}

.about-box {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: 70px;

  align-items: center;

  padding: 70px;

  border: 1px solid rgba(221, 187, 91, 0.25);

  background:
    linear-gradient(
      135deg,
      rgba(255,255,255,0.035),
      rgba(255,255,255,0.01)
    );

  box-shadow:
    0 30px 80px rgba(0,0,0,0.25);
}

.about-number {
  text-align: center;

  border-right: 1px solid rgba(220,190,100,0.3);
}

.about-number span {
  display: block;

  font-family: Georgia, serif;
  font-size: 50px;
  font-weight: bold;

  line-height: 1;

  color: #dfbd65;
}

.about-number small {
  color: #aaa;
  letter-spacing: 6px;
}

.about-text h3 {
  color: #f0cf78;
  font-size: 27px;
  margin-bottom: 25px;
}

.about-text p {
  color: #bfc2ce;
  margin-bottom: 20px;
}


/* ========================================
   HISTORY
   ======================================== */

.history {
  background: #0d1122;
}

.timeline {
  position: relative;
  max-width: 850px;
  margin: auto;
}

.timeline::before {
  content: "";

  position: absolute;
  top: 0;
  bottom: 0;
  left: 100px;

  width: 1px;

  background:
    linear-gradient(
      to bottom,
      transparent,
      #c8a750,
      transparent
    );
}

.timeline-item {
  display: grid;
  grid-template-columns: 200px 1fr;

  position: relative;

  margin-bottom: 55px;
}

.year {
  position: relative;

  color: #e2bf68;

  font-family: Georgia, serif;
  font-size: 28px;
  font-weight: bold;

  text-align: center;
}

.year::after {
  content: "";

  position: absolute;

  top: 50%;
  right: 88px;

  width: 10px;
  height: 10px;

  transform: translateY(-50%);

  border: 2px solid #e2bf68;
  border-radius: 50%;

  background: #0d1122;
}

.timeline-card {
  padding: 28px 35px;

  border: 1px solid rgba(255,255,255,0.08);

  background: rgba(255,255,255,0.025);

  transition: 0.3s;
}

.timeline-card:hover {
  transform: translateX(8px);

  border-color: rgba(220,190,100,0.45);
}

.timeline-card h3 {
  color: #eee;
  font-size: 21px;
  margin-bottom: 8px;
}

.timeline-card p {
  color: #aeb2c1;
  font-size: 14px;
}

.timeline-card.special {
  border-color: rgba(220,190,100,0.5);

  background:
    linear-gradient(
      135deg,
      rgba(214,172,65,0.12),
      rgba(255,255,255,0.02)
    );
}

.timeline-card.special h3 {
  color: #f0cf78;
}


/* ========================================
   MESSAGE
   ======================================== */

.message {
  width: 100%;
  padding: 160px 20px;

  text-align: center;

  background:
    radial-gradient(
      circle at center,
      #25294b,
      #0a0e1c 65%
    );
}

.message-inner {
  max-width: 800px;
  margin: auto;
}

.message-label {
  color: #e2bf68;
  font-size: 11px;
  font-weight: bold;
  letter-spacing: 5px;
}

.message h2 {
  margin-top: 20px;

  font-size: clamp(45px, 7vw, 85px);
  line-height: 1.25;
  letter-spacing: 5px;
}

.message-text {
  margin-top: 35px;

  color: #c3c5d0;
  font-size: 16px;
}

.message-big {
  margin-top: 40px;

  color: #efd078;

  font-size: 22px;
  font-weight: bold;
}

.message-decoration {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 25px;

  margin-top: 55px;

  color: #e1bc61;
}

.message-decoration span:nth-child(2) {
  font-family: Georgia, serif;
  font-size: 55px;
  font-weight: bold;
}


/* ========================================
   THANK YOU
   ======================================== */

.thankyou {
  padding: 120px 20px;

  text-align: center;

  background: #070910;
}

.thankyou-content > p:first-child {
  font-size: 34px;
  font-weight: 900;
  letter-spacing: 2px;
}

.thankyou h2 {
  margin-top: 5px;

  color: #e1bf68;

  font-family: Georgia, serif;
  font-size: 48px;
  letter-spacing: 4px;
}

.thankyou h3 {
  margin-top: 25px;

  font-size: 26px;
  letter-spacing: 4px;
}

.gold-line {
  width: 100px;
  height: 1px;

  margin: 35px auto 20px;

  background: #d6b45d;
}

.date {
  color: #888;

  font-family: Georgia, serif;
  font-size: 14px;
  letter-spacing: 5px;
}


/* ========================================
   FOOTER
   ======================================== */

.footer {
  padding: 30px 20px;

  text-align: center;

  border-top: 1px solid rgba(255,255,255,0.05);

  background: #05060b;

  color: #666;

  font-size: 11px;
}

.footer-note {
  margin-top: 5px;
  color: #444;
}


/* ========================================
   RESPONSIVE
   ======================================== */

@media (max-width: 700px) {

  .header {
    height: 62px;
  }

  .header-inner {
    width: calc(100% - 25px);
  }

  .logo-main {
    font-size: 22px;
  }

  .logo-sub {
    display: none;
  }

  .nav {
    gap: 12px;
  }

  .nav a {
    font-size: 10px;
  }

  .hero {
    min-height: 100svh;
  }

  .anniversary-small {
    font-size: 10px;
    letter-spacing: 3px;
  }

  .number {
    font-size: 45vw;
  }

  .hero h1 {
    font-size: 29px;
    letter-spacing: 2px;
  }

  .hero-message {
    font-size: 13px;
  }

  .section {
    padding: 90px 0;
  }

  .section-title h2 {
    font-size: 27px;
  }

  .about-box {
    grid-template-columns: 1fr;

    gap: 35px;

    padding: 35px 25px;
  }

  .about-number {
    padding-bottom: 30px;
    border-right: none;
    border-bottom: 1px solid rgba(220,190,100,0.3);
  }

  .about-number span {
    font-size: 110px;
  }

  .about-text h3 {
    font-size: 23px;
  }

  .timeline::before {
    left: 18px;
  }

  .timeline-item {
    grid-template-columns: 70px 1fr;
  }

  .year {
    font-size: 16px;
    text-align: left;
    padding-left: 35px;
  }

  .year::after {
    left: 13px;
    right: auto;
  }

  .timeline-card {
    padding: 20px;
  }

  .timeline-card h3 {
    font-size: 18px;
  }

  .message {
    padding: 110px 20px;
  }

  .message h2 {
    font-size: 43px;
    letter-spacing: 2px;
  }

  .message-big {
    font-size: 18px;
  }

  .thankyou h2 {
    font-size: 32px;
  }

  .thankyou h3 {
    font-size: 21px;
  }
}

/* ========================================
   RETURN LINKS — 20th ANNIVERSARY
   ======================================== */

.thankyou-content .return-link {
  margin: 18px 0;
}

.thankyou-content .return-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 340px;
  padding: 17px 38px;

  color: #f4d982;
  text-decoration: none;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 2px;

  border: 1px solid rgba(225, 191, 104, 0.75);
  background:
    linear-gradient(
      135deg,
      rgba(225, 191, 104, 0.16),
      rgba(255, 255, 255, 0.025) 50%,
      rgba(225, 191, 104, 0.08)
    );

  box-shadow:
    0 0 0 1px rgba(225, 191, 104, 0.08) inset,
    0 12px 35px rgba(0, 0, 0, 0.28);

  overflow: hidden;
  transition:
    transform 0.3s ease,
    color 0.3s ease,
    border-color 0.3s ease,
    box-shadow 0.3s ease;
}

/* 四隅の装飾 */
.thankyou-content .return-button::before,
.thankyou-content .return-button::after {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  color: #e2bf68;
  font-family: Georgia, serif;
  font-size: 12px;
}

.thankyou-content .return-button::before {
  content: "✦";
  left: 18px;
}

.thankyou-content .return-button::after {
  content: "✦";
  right: 18px;
}

/* 光が横切る演出 */
.thankyou-content .return-button span {
  position: relative;
  z-index: 2;
}

.thankyou-content .return-button:hover {
  color: #fff5c9;
  border-color: #f0cf78;
  transform: translateY(-4px);

  box-shadow:
    0 0 22px rgba(225, 191, 104, 0.2),
    0 15px 40px rgba(0, 0, 0, 0.38);
}

.thankyou-content .return-button:hover::before,
.thankyou-content .return-button:hover::after {
  animation: returnStar 0.8s ease-in-out infinite alternate;
}

@keyframes returnStar {
  from {
    opacity: 0.45;
    transform: translateY(-50%) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translateY(-50%) scale(1.25);
  }
}

/* スマートフォン */
@media (max-width: 700px) {
  .thankyou-content .return-button {
    min-width: min(300px, 90vw);
    padding: 15px 32px;
    font-size: 13px;
    letter-spacing: 1.5px;
  }
}