/* ============================================
   基础样式 - 纸本白主题
   ============================================ */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  list-style: none;
}

input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
}

/* ---- Typography ---- */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.4;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

h1 { font-size: var(--fs-5xl); }
h2 { font-size: var(--fs-4xl); }
h3 { font-size: var(--fs-3xl); }
h4 { font-size: var(--fs-2xl); }
h5 { font-size: var(--fs-xl); }
h6 { font-size: var(--fs-lg); }

p {
  margin-bottom: var(--sp-5);
  line-height: 1.8;
  color: var(--color-text-secondary);
}

/* ---- Selection ---- */
::selection {
  background: rgba(26, 67, 50, 0.12);
  color: var(--wct-green);
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-warm);
}

::-webkit-scrollbar-thumb {
  background: var(--color-divider);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-light);
}

/* ---- Utility ---- */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.hidden { display: none !important; }

/* ---- Animations ---- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.lazy-img {
  opacity: 0;
  transition: opacity 0.4s ease;
}

.lazy-img.loaded {
  opacity: 1;
}