/* =========================
   Base
========================= */
:root {
  --blue: #2563eb;
  --blue-dark: #1e40af;
  --emerald: #10b981;
  --violet: #8b5cf6;
  --cyan: #0891b2;
  --slate: #334155;
  --amber: #f59e0b;

  --bg: #f8fafc;
  --white: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 14px 30px rgba(15, 23, 42, 0.08);
  --shadow-hover: 0 18px 38px rgba(15, 23, 42, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  font-family: "Inter", "Noto Sans JP", system-ui, sans-serif;
  color: var(--text);
  background: var(--bg);
}

body {
  margin: 0;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

::selection {
  background: rgba(37, 99, 235, 0.16);
}

/* =========================
   Header
========================= */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 4vw, 48px);
  color: #fff;
  background: linear-gradient(90deg, var(--blue), #6366f1, var(--violet));
  box-shadow: 0 2px 10px rgba(15, 23, 42, 0.14);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-icon {
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  color: var(--blue);
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.16);
}

.brand-icon svg {
  width: 26px;
  height: 26px;
}

.brand-name {
  font-size: clamp(1.05rem, 2.2vw, 1.45rem);
  font-weight: 800;
  letter-spacing: 0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-message {
  margin: 0;
  padding: 7px 12px;
  font-size: 0.95rem;
  font-weight: 700;
  white-space: nowrap;
  background: rgba(30, 64, 175, 0.42);
  border-radius: 10px;
}

.header-message-sp {
  display: none;
}

/* =========================
   Hero
========================= */
.hero {
  padding: clamp(44px, 6vw, 72px) 20px clamp(30px, 5vw, 54px);
  background: #fff;
}

.hero-inner {
  max-width: 1040px;
  margin: 0 auto;
  text-align: center;
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(2rem, 4.4vw, 3.35rem);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.04em;
  background: linear-gradient(90deg, var(--blue), #4f46e5, var(--emerald));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-wrap: balance;
  overflow-wrap: normal;
  word-break: keep-all;
}

.hero-title-main {
  display: inline-block;
  white-space: nowrap;
}

.hero-principle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 18px;
  padding: 12px 18px;
  color: #1e293b;
  background: linear-gradient(90deg, #eff6ff, #ecfdf5);
  border: 1px solid #bfdbfe;
  border-radius: 999px;
  font-size: clamp(0.95rem, 1.7vw, 1.08rem);
  line-height: 1.7;
  font-weight: 800;
}

.hero p {
  margin: 0;
  color: #475569;
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.9;
  font-weight: 600;
}

.hero strong {
  color: var(--violet);
}

/* =========================
   Tool Cards
========================= */
.tools {
  padding: 0 20px 48px;
}

.tools-grid {
  max-width: 960px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.tool-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 142px;
  padding: 22px 18px;
  text-align: center;
  background: #fff;
  border: 1px solid #dbeafe;
  border-radius: 18px;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.tool-icon {
  display: grid;
  place-items: center;
  width: 54px;
  height: 54px;
  margin-bottom: 10px;
  border-radius: 999px;
}

.tool-icon svg {
  width: 28px;
  height: 28px;
}

.tool-name {
  font-size: 1.08rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.tool-note {
  color: var(--muted);
  font-size: 0.82rem;
}

.tool-google .tool-icon { color: var(--blue); background: linear-gradient(135deg, #bfdbfe, #ecfeff); }
.tool-github .tool-icon { color: #374151; background: linear-gradient(135deg, #d1d5db, #ede9fe); }
.tool-v0 .tool-icon { color: var(--emerald); background: linear-gradient(135deg, #a7f3d0, #dbeafe); }
.tool-lovable .tool-icon { color: var(--violet); background: linear-gradient(135deg, #ddd6fe, #dbeafe); }

.tool-google:hover { border-color: var(--blue); }
.tool-github:hover { border-color: #64748b; }
.tool-v0:hover { border-color: var(--emerald); }
.tool-lovable:hover { border-color: var(--violet); }

/* =========================
   Roadmap
========================= */
main {
  padding: 0 20px;
}

.roadmap {
  max-width: 1040px;
  margin: 0 auto 56px;
}

.roadmap h2 {
  margin: 0 0 20px;
  color: var(--blue);
  font-size: clamp(1.25rem, 2.4vw, 1.65rem);
  font-weight: 800;
}

.phase-list {
  display: grid;
  gap: 18px;
}

.phase-card {
  --phase-color: var(--blue);
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 28px;
  align-items: center;
  padding: 22px 24px;
  background: #fff;
  border: 1px solid rgba(226, 232, 240, 0.95);
  border-left: 5px solid var(--phase-color);
  border-radius: 18px;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.phase-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.phase-card.is-current {
  border-color: rgba(37, 99, 235, 0.35);
  border-left-color: var(--phase-color);
}

.phase-left {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.phase-icon {
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  color: #fff;
  background: var(--phase-color);
  border-radius: 12px;
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.12);
}

.phase-icon svg {
  width: 24px;
  height: 24px;
}

.phase-title {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.phase-number {
  color: var(--phase-color);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.phase-name {
  color: var(--phase-color);
  font-size: 1.08rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.phase-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-width: 0;
}

.phase-copy {
  min-width: 0;
}

.phase-subtitle {
  margin: 0 0 7px;
  color: #334155;
  font-size: 0.95rem;
  font-weight: 700;
}

.phase-can {
  display: flex;
  align-items: flex-start;
  gap: 6px;
  margin: 0;
  color: var(--phase-color);
  font-size: 0.92rem;
  line-height: 1.55;
  font-weight: 800;
}

.phase-can svg {
  flex: 0 0 auto;
  width: 16px;
  height: 16px;
  margin-top: 3px;
}

.phase-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

.status-badge {
  padding: 7px 10px;
  color: var(--emerald);
  background: #ecfdf5;
  border: 1px solid #a7f3d0;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 800;
  white-space: nowrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 0.8rem;
  font-weight: 800;
  transition: background 0.2s ease, transform 0.2s ease;
  white-space: nowrap;
}

.button:hover {
  transform: translateY(-1px);
}

.button-primary {
  color: #fff;
  background: var(--blue);
}

.button-primary:hover {
  background: var(--blue-dark);
}

.button-sub {
  color: #4338ca;
  background: #e0e7ff;
}

.button-sub:hover {
  background: #c7d2fe;
}

/* Phase colors */
.phase-blue { --phase-color: var(--blue); }
.phase-emerald { --phase-color: var(--emerald); }
.phase-violet { --phase-color: var(--violet); }
.phase-cyan { --phase-color: var(--cyan); }
.phase-slate { --phase-color: var(--slate); }
.phase-amber { --phase-color: var(--amber); }

/* =========================
   Notice & Footer
========================= */
.notice {
  max-width: 860px;
  margin: 0 auto 42px;
  padding: 0 20px;
}

.notice-box {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px;
  background: linear-gradient(90deg, #fffbeb, #ecfdf5, #fff);
  border-left: 5px solid var(--emerald);
  border-radius: 16px;
  box-shadow: var(--shadow);
}

.notice-icon {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  color: #fff;
  background: var(--emerald);
  border-radius: 999px;
}

.notice-icon svg {
  width: 20px;
  height: 20px;
}

.notice p {
  margin: 0;
  color: #475569;
  font-weight: 600;
  line-height: 1.7;
}

.notice strong {
  color: var(--blue);
}

.site-footer {
  display: flex;
  justify-content: center;
  padding: 28px 20px;
  color: #94a3b8;
  background: #fff;
  border-top: 1px solid var(--border);
}


/* =========================
   Scroll Top Button
========================= */
.scroll-top-button {
  position: fixed;
  right: clamp(16px, 3vw, 28px);
  bottom: clamp(16px, 3vw, 28px);
  z-index: 50;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 46px;
  padding: 11px 14px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), #6366f1, var(--violet));
  border: 1px solid rgba(255, 255, 255, 0.45);
  border-radius: 999px;
  box-shadow: 0 16px 32px rgba(37, 99, 235, 0.28);
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.scroll-top-button.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top-button:hover {
  box-shadow: 0 20px 42px rgba(37, 99, 235, 0.36);
  transform: translateY(-2px);
}

.scroll-top-button:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.24);
  outline-offset: 4px;
}

.scroll-top-button svg {
  width: 17px;
  height: 17px;
  stroke-width: 3;
}

/* =========================
   Responsive
========================= */
@media (max-width: 900px) {
  .tools-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .phase-card {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .phase-content {
    align-items: flex-start;
  }
}

@media (max-width: 680px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .header-message-pc {
    display: none;
  }

  .header-message-sp {
    display: inline;
  }

  .hero p br {
    display: none;
  }

  .hero-title-main {
    display: inline;
    white-space: normal;
  }

  .hero-principle {
    display: block;
    border-radius: 18px;
  }

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

  .phase-card {
    padding: 18px;
  }

  .phase-content {
    flex-direction: column;
  }

  .phase-actions {
    width: 100%;
    flex-wrap: wrap;
  }

  .button {
    flex: 1 1 130px;
  }

  .phase-name {
    white-space: normal;
  }

  .scroll-top-button {
    right: 14px;
    bottom: 14px;
    min-height: 42px;
    padding: 10px 12px;
    font-size: 0.72rem;
  }

}