/* ============================================================================
 * tokens.css — CarbForge Design Tokens
 *
 * Source of truth: docs/specs/feature-brand-site.md §5.8 视觉系统
 * Style lock: Modern Minimal (BONE ground + STEEL text + EMBER accent)
 *
 * Do not edit without a Spec revision. All colors, typography, spacing and
 * motion values here are derived from the brand manual and the WCAG contrast
 * audit logged at the end of §5.8 of the Spec.
 * ========================================================================== */

:root {
  /* Palette —— 来自品牌手册，Modern Minimal 下的使用规则 */
  --color-bg:          #FAFAF8;      /* 略白于 BONE，避免和 UI chrome 混淆 */
  --color-bg-alt:      #F0F0EC;      /* BONE，用于 section 分隔 */
  --color-text:        #161A20;      /* STEEL 主文 */
  --color-text-muted:  #6B7280;      /* MUTED 次文 */
  --color-accent:      #E85620;      /* EMBER 唯一强调色，仅 CTA / 数字高亮 */
  --color-accent-dark: #B43012;      /* EMBER_DEEP hover */
  --color-hairline:    #D7D7D2;

  /* Typography */
  --font-display: "Inter", "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body:    "Inter", "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, "Menlo", monospace;   /* 用于数字/SKU */

  --fs-display-1: clamp(2.5rem, 6vw, 5rem);    /* Hero 标题 */
  --fs-display-2: clamp(2rem, 4vw, 3.5rem);    /* Section 标题 */
  --fs-h3:        1.5rem;
  --fs-body:      1.125rem;                    /* 18px，偏大阅读友好 */
  --fs-small:     0.875rem;

  --lh-tight:     1.1;
  --lh-body:      1.6;

  --fw-regular:   400;
  --fw-medium:    500;
  --fw-semibold:  600;
  /* 不用 bold 800+，minimal 风格忌肥大 */

  /* Spacing scale —— 8-point grid */
  --sp-1:  0.25rem;
  --sp-2:  0.5rem;
  --sp-3:  1rem;
  --sp-4:  1.5rem;
  --sp-5:  2rem;
  --sp-6:  3rem;
  --sp-7:  4rem;
  --sp-8:  6rem;
  --sp-9:  8rem;

  /* Layout */
  --max-width:        1280px;
  --gutter:           1.5rem;
  --section-py:       clamp(4rem, 10vw, 8rem);  /* 章节上下 padding 大 */
  --radius:           0;                         /* 全站无圆角 */
  --radius-soft:      2px;                       /* 卡片 / 按钮最多 2px */
  --hairline:         1px solid var(--color-hairline);

  /* Motion */
  --ease:             cubic-bezier(0.2, 0, 0, 1);
  --dur-fast:         150ms;
  --dur-base:         250ms;
  --dur-slow:         400ms;
}

/* ----------------------------------------------------------------------------
 * RTL overrides — Arabic (/ar/).
 *
 * Logical properties (margin-inline-*, padding-inline-*, inset-inline-*,
 * border-inline-*) used throughout main.css handle direction flipping
 * automatically. This block is reserved for the few rules that cannot be
 * expressed with logical properties (e.g. caret/chevron rotations, mirrored
 * gradients, decorative directional glyphs). Currently empty by design.
 * -------------------------------------------------------------------------- */

[dir="rtl"] {
  /* reserved for future direction-specific overrides */
}