/* ================================================
   ROOT LLC - Global Styles
   Apple / Google / Nike / Stripe / Notion統合デザイン
   ================================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-padding-top: 150px; /* Global offset for all anchor links */
}

body {
  font-family: var(--font-sans), var(--font-sans-jp);
  font-size: var(--text-lg);
  line-height: var(--leading-loose);
  letter-spacing: var(--tracking-wide);
  color: var(--root-black);
  background-color: var(--root-white);
  font-weight: var(--font-normal);
  overflow-x: hidden;
}

/* ===== Typography Hierarchy ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  color: var(--root-black);
  margin: 0;
}

h1 {
  font-size: var(--text-5xl);
  letter-spacing: var(--tracking-tighter);
  line-height: 1.15;
}

h2 {
  font-size: var(--text-4xl);
  letter-spacing: var(--tracking-tight);
  line-height: 1.2;
}

h3 {
  font-size: var(--text-3xl);
  letter-spacing: var(--tracking-tight);
  line-height: 1.25;
}

h4 {
  font-size: var(--text-2xl);
  line-height: 1.35;
}

h5 {
  font-size: var(--text-xl);
  line-height: 1.4;
}

h6 {
  font-size: var(--text-lg);
  line-height: 1.5;
}

p {
  margin: 0;
  font-size: var(--text-lg);
  line-height: var(--leading-loose);
  letter-spacing: var(--tracking-wide);
  color: var(--root-black);
}

/* ===== Links ===== */
a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition-base);
}

a:hover {
  color: var(--root-accent);
}

/* ===== Images ===== */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== Lists ===== */
ul, ol {
  list-style: none;
  margin: 0;
  padding: 0;
}

/* ===== Buttons ===== */
button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
  transition: var(--transition-base);
}

button:focus {
  outline: 2px solid var(--root-accent);
  outline-offset: 2px;
}

/* ===== Utility Classes ===== */

/* Container */
.container {
  width: 100%;
  max-width: var(--max-width-content);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.container-wide {
  max-width: var(--max-width-wide);
}

.container-narrow {
  max-width: var(--max-width-narrow);
}

/* Section Spacing */
.section {
  padding: var(--space-16) 0;
}

.section-lg {
  padding: var(--space-20) 0;
}

.section-sm {
  padding: var(--space-12) 0;
}

/* Text Alignment */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

/* Text Colors */
.text-gray {
  color: var(--root-gray-600);
}

.text-accent {
  color: var(--root-accent);
}

/* Caption Text */
.caption {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--root-gray-600);
  letter-spacing: var(--tracking-normal);
}

/* Display Text */
.display {
  font-size: clamp(3rem, 6vw, 5rem);
  font-weight: var(--font-semibold);
  letter-spacing: var(--tracking-tighter);
  line-height: 1.1;
}

/* Lead Text */
.lead {
  font-size: var(--text-xl);
  line-height: var(--leading-relaxed);
  color: var(--root-gray-600);
}

/* ===== Layout Utilities ===== */

/* Flexbox */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid */
.grid {
  display: grid;
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }

/* ===== Spacing Utilities ===== */
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }

.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }

/* ===== Animation Utilities ===== */

/* Fade In (Scroll Animation) */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

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

/* Stagger Animation (for multiple items) */
.fade-in-stagger {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

.fade-in-stagger:nth-child(1) { transition-delay: 0.1s; }
.fade-in-stagger:nth-child(2) { transition-delay: 0.2s; }
.fade-in-stagger:nth-child(3) { transition-delay: 0.3s; }
.fade-in-stagger:nth-child(4) { transition-delay: 0.4s; }
.fade-in-stagger:nth-child(5) { transition-delay: 0.5s; }

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

/* ===== Responsive Typography ===== */
@media (max-width: 1024px) {
  html {
    font-size: 15px;
  }
  
  h1 {
    font-size: var(--text-4xl);
  }
  
  h2 {
    font-size: var(--text-3xl);
  }
  
  .section {
    padding: var(--space-12) 0;
  }
  
  .section-lg {
    padding: var(--space-16) 0;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }
  
  h1 {
    font-size: var(--text-3xl);
  }
  
  h2 {
    font-size: var(--text-2xl);
  }
  
  h3 {
    font-size: var(--text-xl);
  }
  
  .container {
    padding: 0 var(--space-3);
  }
  
  .section {
    padding: var(--space-8) 0;
  }
  
  .section-lg {
    padding: var(--space-12) 0;
  }
  
  .section-sm {
    padding: var(--space-6) 0;
  }
}

/* ===== Selection ===== */
::selection {
  background-color: var(--root-accent);
  color: var(--root-white);
}

::-moz-selection {
  background-color: var(--root-accent);
  color: var(--root-white);
}

/* ===== Scrollbar (Webkit) ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--root-gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--root-gray-400);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--root-gray-600);
}

/* ===== Focus Visible ===== */
:focus-visible {
  outline: 2px solid var(--root-accent);
  outline-offset: 2px;
}