/* =============================================================
   至名能源 · 统一设计系统 (Design System)
   风格：工业稳重 · 高端制造
   version 3.1 — 2026-07-0907-08
   ============================================================= */

/* ---------- 设计令牌 (Design Tokens) ---------- */
:root {
  /* 品牌主色 · 精炼工业蓝 */
  --brand:            #1f6fd0;
  --brand-strong:     #1559ad;
  --brand-light:      #4a90e2;
  --brand-soft:       #eaf2fc;

  /* 能源辅助色 · 琥珀金（用于 CTA / 高亮 / 数字强调，克制使用）*/
  --accent:           #f5a11d;
  --accent-strong:    #e07b12;
  --accent-soft:      #fff4e2;

  /* 深色工业底 · 石墨/深海军蓝 */
  --dark-1:           #0a121f;
  --dark-2:           #0f1d33;
  --dark-3:           #16273f;
  --dark-4:           #1d3350;

  /* 中性灰阶 */
  --gray-50:          #f6f8fb;
  --gray-100:         #eef2f7;
  --gray-200:         #e2e8f0;
  --gray-300:         #cbd5e1;
  --gray-400:         #94a3b8;
  --gray-500:         #64748b;
  --gray-600:         #475569;
  --gray-700:         #334155;
  --gray-800:         #1e293b;

  /* 文本 */
  --t-strong:         #0d1b2a;
  --t:                #3a4a5c;
  --t-soft:           #6b7a8c;
  --t-invert:         rgba(255,255,255,.94);
  --t-invert-soft:    rgba(255,255,255,.64);
  --t-invert-faint:   rgba(255,255,255,.42);

  /* 分隔线 */
  --line:             #e4e9f0;
  --line-strong:      #d3dbe6;
  --line-dark:        rgba(255,255,255,.10);

  /* 金属质感面板渐变 */
  --metal:            linear-gradient(160deg, #1b2c46 0%, #12213a 60%, #0e1b30 100%);
  --metal-hi:         inset 0 1px 0 rgba(255,255,255,.07), inset 0 0 0 1px rgba(255,255,255,.05);
  --dark-bg:          radial-gradient(1200px 600px at 80% -10%, rgba(31,111,208,.20), transparent 60%),
                      radial-gradient(900px 500px at 10% 110%, rgba(245,161,29,.08), transparent 55%),
                      linear-gradient(180deg, #0b1424 0%, #0d1b30 100%);

  /* 阴影 */
  --shadow-sm:        0 1px 3px rgba(13,27,42,.08);
  --shadow:           0 6px 24px rgba(13,27,42,.10);
  --shadow-md:        0 12px 40px rgba(13,27,42,.14);
  --shadow-lg:        0 24px 60px rgba(13,27,42,.20);
  --shadow-accent:    0 10px 30px rgba(224,123,18,.32);
  --shadow-brand:     0 10px 30px rgba(31,111,208,.30);

  /* 圆角 */
  --r-sm:             6px;
  --r:                10px;
  --r-lg:             16px;
  --r-xl:             22px;
  --r-pill:           999px;

  /* 间距节奏 */
  --space-1:          4px;
  --space-2:          8px;
  --space-3:          12px;
  --space-4:          16px;
  --space-5:          24px;
  --space-6:          32px;
  --space-7:          48px;
  --space-8:          64px;
  --space-9:          80px;
  --space-10:         96px;
  --section-y:        clamp(56px, 8vw, 112px);

  /* 字号（流体） */
  --fs-hero:          clamp(2.1rem, 1.2rem + 3.2vw, 3.6rem);
  --fs-h2:            clamp(1.55rem, 1.1rem + 1.5vw, 2.2rem);
  --fs-h3:            1.28rem;
  --fs-lead:          clamp(1rem, .95rem + .4vw, 1.2rem);
  --fs-body:          1rem;
  --fs-sm:            .875rem;
  --fs-xs:            .78rem;

  /* 版心 */
  --container:        1240px;

  /* 字族 */
  --font:             "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system,
                      BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --font-num:         "DIN Alternate", "Bahnschrift", "Segoe UI", var(--font);

  --ease:             cubic-bezier(.22,.61,.36,1);
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--t);
  background: var(--gray-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; border: 0; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: 0; background: none; }
h1, h2, h3, h4 { color: var(--t-strong); line-height: 1.25; font-weight: 700; letter-spacing: -.01em; }
ul { list-style: none; }

/* ---------- 版心容器 ---------- */
.ds-container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
@media (max-width: 640px) { .ds-container { padding: 0 18px; } }

/* ---------- 区块 ---------- */
.ds-section { padding: var(--section-y) 0; position: relative; }

.ds-section--dark {
  background: var(--dark-bg);
  color: var(--t-invert);
}
.ds-section--soft { background: var(--gray-50); }
.ds-section--tight { padding: clamp(28px, 4vw, 56px) 0; }

/* ---------- 区块标题 ---------- */
.ds-head { text-align: center; max-width: 760px; margin: 0 auto clamp(36px, 5vw, 60px); }
.ds-head .eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: var(--fs-xs); font-weight: 700; letter-spacing: .16em; text-transform: uppercase;
  color: var(--brand);
  margin-bottom: 14px;
}
.ds-section--dark .ds-head .eyebrow { color: var(--accent); }
.ds-head .eyebrow::before {
  content: ""; width: 26px; height: 2px; background: currentColor; display: inline-block;
}
.ds-head h2 { font-size: var(--fs-h2); margin-bottom: 14px; }
.ds-section--dark .ds-head h2 { color: #fff; }
.ds-head p { font-size: var(--fs-lead); color: var(--t-soft); }
.ds-section--dark .ds-head p { color: var(--t-invert-soft); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 14px 28px;
  font-size: .96rem; font-weight: 600; letter-spacing: .01em;
  border-radius: var(--r-pill);
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s var(--ease), color .25s var(--ease), border-color .25s var(--ease);
  white-space: nowrap; cursor: pointer;
}
.btn svg { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-2px); }

.btn--primary { background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%); color: #fff; box-shadow: var(--shadow-accent); }
.btn--primary:hover { box-shadow: 0 16px 38px rgba(224,123,18,.42); }

.btn--brand { background: linear-gradient(135deg, var(--brand-light) 0%, var(--brand-strong) 100%); color: #fff; box-shadow: var(--shadow-brand); }
.btn--brand:hover { box-shadow: 0 16px 38px rgba(31,111,208,.42); }

.btn--ghost { background: rgba(255,255,255,.06); color: #fff; border: 1px solid rgba(255,255,255,.32); }
.btn--ghost:hover { background: rgba(255,255,255,.14); border-color: rgba(255,255,255,.6); }

.btn--outline { background: transparent; color: var(--brand); border: 1.5px solid var(--brand); }
.btn--outline:hover { background: var(--brand); color: #fff; }

.btn--sm { padding: 10px 20px; font-size: .875rem; }

/* ---------- 文字链接（带箭头） ---------- */
.link-arrow {
  display: inline-flex; align-items: center; gap: 6px;
  font-weight: 600; color: var(--brand);
  transition: gap .25s var(--ease), color .25s var(--ease);
}
.link-arrow svg { width: 16px; height: 16px; transition: transform .25s var(--ease); }
.link-arrow:hover { color: var(--brand-strong); gap: 10px; }

/* ---------- 滚动入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .08s; }
.reveal[data-delay="2"] { transition-delay: .16s; }
.reveal[data-delay="3"] { transition-delay: .24s; }
.reveal[data-delay="4"] { transition-delay: .32s; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}