/* ============================================
   P04 Seminar 2026
   Concept: Brutalist × Underground Event
   Palette: mustard / ecru / deep green
   ============================================ */

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg:       #F0EBE0;
  --color-bg-alt:   #E6E0D2;
  --color-green:    #1F3A2E;
  --color-mustard:  #D4A017;
  --color-text:     #1F3A2E;
  --color-text-sub: #5C6B5E;
  --color-rule:     #1F3A2E;
  --color-rule-lt:  #C4BBA8;

  --font-display: "Big Shoulders Display", sans-serif;
  --font-body:    "Outfit", sans-serif;
  --font-jp:      "Zen Kaku Gothic New", sans-serif;

  --container-max: 1100px;
  --container-pad: 40px;

  --transition: 0.25s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--color-mustard); }

ul { list-style: none; }

/* ---------- Header ---------- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px var(--container-pad);
  border-bottom: 3px solid var(--color-rule);
  background: var(--color-bg);
}

.header__brand {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: 0.04em;
}

.header__nav {
  display: flex;
  gap: 28px;
  align-items: center;
}

.header__link {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.header__link--cta {
  background: var(--color-green);
  color: var(--color-bg);
  padding: 8px 20px;
  transition: background var(--transition);
}
.header__link--cta:hover {
  background: var(--color-mustard);
  color: var(--color-green);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 100px var(--container-pad) 80px;
  overflow: hidden;
}

/* Diagonal stripes */
.hero__bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
  z-index: 0;
}

.hero__stripe {
  position: absolute;
  background: var(--color-mustard);
  transform: rotate(-12deg);
  transform-origin: top left;
}

.hero__stripe--1 {
  width: 120%;
  height: 80px;
  top: 15%;
  left: -10%;
  opacity: 0.12;
}

.hero__stripe--2 {
  width: 120%;
  height: 40px;
  top: 60%;
  left: -10%;
  opacity: 0.08;
}

.hero__stripe--3 {
  width: 120%;
  height: 160px;
  top: 75%;
  left: -10%;
  opacity: 0.05;
}

.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
}

.hero__meta {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 40px;
}

.hero__date-label,
.hero__location {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-sub);
}

.hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 0.88;
  letter-spacing: -0.02em;
  margin-bottom: 32px;
}

.hero__title-line {
  display: block;
  font-size: clamp(72px, 16vw, 180px);
}

.hero__title-year {
  display: block;
  font-size: clamp(48px, 10vw, 120px);
  color: var(--color-mustard);
  margin-top: 8px;
}

.hero__subtitle {
  font-family: var(--font-jp);
  font-size: 16px;
  line-height: 2;
  color: var(--color-text-sub);
  margin-bottom: 56px;
}

/* ---------- Countdown ---------- */
.countdown {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 8px;
  padding: 32px 0;
  border-top: 3px solid var(--color-rule);
  border-bottom: 3px solid var(--color-rule);
}

.countdown__item { text-align: center; min-width: 72px; }

.countdown__number {
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 64px);
  font-weight: 900;
  letter-spacing: -0.02em;
  display: block;
  line-height: 1;
}

.countdown__label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-sub);
  margin-top: 8px;
  display: block;
}

.countdown__sep {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 900;
  color: var(--color-mustard);
  line-height: 1;
  padding-top: 4px;
}

/* ---------- Speakers ---------- */
.speakers {
  padding: 100px var(--container-pad);
  max-width: var(--container-max);
  margin: 0 auto;
  border-top: 3px solid var(--color-rule);
}

.speakers__header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 56px;
}

.speakers__title {
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 80px);
  font-weight: 900;
  letter-spacing: -0.02em;
}

.speakers__count {
  font-size: 13px;
  color: var(--color-text-sub);
  letter-spacing: 0.06em;
}

.speakers__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px 24px;
}

.speaker__photo {
  overflow: hidden;
  margin-bottom: 16px;
  border: 3px solid var(--color-rule);
}

.speaker__photo img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  filter: grayscale(60%) contrast(1.1);
  transition: filter 0.4s ease;
}

.speaker:hover .speaker__photo img {
  filter: grayscale(0%) contrast(1);
}

.speaker__name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 2px;
}

.speaker__role {
  font-size: 12px;
  color: var(--color-text-sub);
}

/* ---------- Schedule ---------- */
.schedule {
  padding: 100px var(--container-pad);
  max-width: var(--container-max);
  margin: 0 auto;
  border-top: 3px solid var(--color-rule);
}

.schedule__title {
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 80px);
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 56px;
}

.schedule__days {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.schedule__day-title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding-bottom: 16px;
  border-bottom: 3px solid var(--color-rule);
  margin-bottom: 0;
}

.schedule__item {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--color-rule-lt);
  transition: background-color var(--transition);
}

.schedule__item:hover {
  background-color: var(--color-bg-alt);
  margin: 0 -12px;
  padding-left: 12px;
  padding-right: 12px;
}

.schedule__item--break {
  opacity: 0.5;
}

.schedule__time {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-mustard);
}

.schedule__talk {
  display: block;
  font-weight: 500;
  margin-bottom: 2px;
}

.schedule__speaker {
  display: block;
  font-size: 12px;
  color: var(--color-text-sub);
}

/* ---------- Register ---------- */
.register {
  padding: 100px var(--container-pad);
  max-width: var(--container-max);
  margin: 0 auto;
  border-top: 3px solid var(--color-rule);
}

.register__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}

.register__heading {
  font-family: var(--font-display);
  font-size: clamp(56px, 8vw, 96px);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.02em;
}

.register__dot { color: var(--color-mustard); }

.register__text {
  font-family: var(--font-jp);
  color: var(--color-text-sub);
  margin-bottom: 32px;
  line-height: 1.9;
}

.register__pricing {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 40px;
}

.register__price-card {
  padding: 24px 16px;
  border: 2px solid var(--color-rule);
  text-align: center;
}

.register__price-card--regular {
  background: var(--color-green);
  color: var(--color-bg);
  border-color: var(--color-green);
}

.register__price-label {
  display: block;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.register__price-amount {
  display: block;
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 900;
  margin-bottom: 4px;
}

.register__price-note {
  font-size: 11px;
  color: var(--color-text-sub);
}

.register__price-card--regular .register__price-note {
  color: rgba(240, 235, 224, 0.6);
}

.register__form {
  display: flex;
  gap: 0;
}

.register__input {
  flex: 1;
  padding: 14px 20px;
  border: 2px solid var(--color-rule);
  border-right: none;
  background: transparent;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--color-text);
  outline: none;
}
.register__input::placeholder { color: var(--color-rule-lt); }
.register__input:focus { border-color: var(--color-mustard); }

.register__btn {
  padding: 14px 32px;
  background: var(--color-green);
  color: var(--color-bg);
  border: 2px solid var(--color-green);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all var(--transition);
}
.register__btn:hover {
  background: var(--color-mustard);
  border-color: var(--color-mustard);
  color: var(--color-green);
}

/* ---------- Footer ---------- */
.footer {
  border-top: 3px solid var(--color-rule);
  padding: 24px var(--container-pad);
  max-width: var(--container-max);
  margin: 0 auto;
}

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

.footer__brand {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 900;
}

.footer__links {
  display: flex;
  gap: 24px;
}

.footer__links a {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--color-text-sub);
}

.footer__copy {
  font-size: 10px;
  color: var(--color-text-sub);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
  :root { --container-pad: 20px; }

  .header { padding: 16px var(--container-pad); }
  .header__brand { font-size: 18px; }
  .header__nav { gap: 16px; }
  .header__link { font-size: 12px; }
  .header__link--cta { padding: 6px 14px; }

  .hero { padding-top: 80px; }
  .hero__meta {
    flex-direction: column;
    gap: 8px;
  }
  .hero__subtitle { font-size: 14px; }

  .countdown__number { font-size: 36px; }
  .countdown__sep { font-size: 28px; }
  .countdown__item { min-width: 56px; }

  .speakers { padding: 80px var(--container-pad); }
  .speakers__header { flex-direction: column; gap: 8px; }
  .speakers__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px 16px;
  }

  .schedule { padding: 80px var(--container-pad); }
  .schedule__days {
    grid-template-columns: 1fr;
    gap: 56px;
  }

  .register { padding: 80px var(--container-pad); }
  .register__inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .register__pricing {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .register__form { flex-direction: column; }
  .register__input { border-right: 2px solid var(--color-rule); }
}

@media (max-width: 480px) {
  .header__nav { gap: 10px; }
  .header__link { font-size: 11px; }

  .hero__title-line { font-size: 48px; }
  .hero__title-year { font-size: 36px; }

  .countdown { flex-wrap: wrap; gap: 4px; }
  .countdown__item { min-width: 48px; }
  .countdown__number { font-size: 28px; }
  .countdown__sep { font-size: 22px; }

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

  .schedule__item {
    grid-template-columns: 56px 1fr;
    gap: 12px;
  }

  .footer__inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}