/* 言者新知专栏 - 极简克制风格 */

/* ===== 全局变量 ===== */
:root {
  --color-nav-bg: #2d2d2d;
  --color-brand-red: #D12C25;
  --color-brand-red-hover: #b8231d;
  --color-bg-warm: #FAF9F5;
  --color-card-bg: #ffffff;
  --color-text-dark: #2c2c2c;
  --color-text-gray: #777777;
  --color-text-light: #aaaaaa;
  --color-border-main: #e8e6e1;
  --color-border-light: #f0eeea;
  --color-quote-bg: #f5f3ef;
  
  --font-stack: Arial, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --line-height-base: 1.8;

  /* 字体层级（严格6级） */
  --fs-display: 2.25rem;   /* 首页大标题 */
  --fs-h1: 1.75rem;        /* 文章标题 */
  --fs-h2: 1.2rem;         /* 章节标题 */
  --fs-body: 1rem;         /* 正文 16px */
  --fs-small: 0.875rem;    /* 辅助信息 14px */
  --fs-tiny: 0.8rem;       /* 分类标签 ~13px */
}

/* ===== 重置与基础 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-stack);
  font-size: var(--fs-body);
  line-height: var(--line-height-base);
  color: var(--color-text-dark);
  background-color: var(--color-bg-warm);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
}

a {
  color: var(--color-brand-red);
  text-decoration: none;
}

/* ===== 导航栏 ===== */
.navbar {
  background-color: var(--color-nav-bg);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.navbar-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  color: white;
  font-size: var(--fs-body);
  font-weight: 600;
  text-decoration: none;
  letter-spacing: 1px;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
  font-size: var(--fs-small);
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: white;
}

/* ===== 首页 ===== */
.hero {
  max-width: 700px;
  margin: 0 auto;
  padding: 10rem 2rem 4rem;
  text-align: center;
}

.hero-title {
  font-size: var(--fs-display);
  font-weight: 600;
  letter-spacing: 3px;
  margin-bottom: 1rem;
  color: var(--color-text-dark);
}

.hero-subtitle {
  font-size: var(--fs-body);
  color: var(--color-text-gray);
  margin-bottom: 1.5rem;
  font-weight: 400;
}

.hero-slogan {
  font-size: var(--fs-small);
  color: var(--color-text-light);
  margin-bottom: 3rem;
  letter-spacing: 0.5px;
}

.cta-button {
  display: inline-block;
  padding: 0.75rem 2rem;
  background-color: var(--color-brand-red);
  color: white;
  text-decoration: none;
  font-size: var(--fs-small);
  border-radius: 3px;
  transition: background-color 0.2s ease;
  font-weight: 500;
  letter-spacing: 0.5px;
}

.cta-button:hover {
  background-color: var(--color-brand-red-hover);
}

.manifesto {
  max-width: 550px;
  margin: 4rem auto 8rem;
  padding: 0 2rem;
  text-align: center;
}

.manifesto-inner {
  border-top: 1px solid var(--color-border-main);
  border-bottom: 1px solid var(--color-border-main);
  padding: 2.5rem 0;
  text-align: center;
}

.manifesto-text {
  font-size: var(--fs-small);
  color: var(--color-text-gray);
  line-height: 2;
}

.manifesto-author {
  margin-top: 1.5rem;
  font-size: var(--fs-small);
  color: var(--color-text-light);
}

/* ===== 目录页 ===== */
.catalog-container {
  max-width: 1100px;
  margin: 3rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 4rem;
  align-items: start;
}

.toc-sidebar {
  position: sticky;
  top: 80px;
}

.toc-section {
  margin-bottom: 2rem;
}

.toc-section-title {
  font-size: var(--fs-tiny);
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 0.75rem;
  font-weight: 600;
}

.toc-list {
  list-style: none;
}

.toc-item {
  margin-bottom: 0.25rem;
}

.toc-item a {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0 0.5rem 1rem;
  color: var(--color-text-dark);
  text-decoration: none;
  font-size: var(--fs-small);
  border-left: 2px solid transparent;
  transition: all 0.2s ease;
}

.toc-item a:hover {
  color: var(--color-brand-red);
}

.toc-item.active a {
  border-left-color: var(--color-brand-red);
  color: var(--color-brand-red);
  font-weight: 500;
}

.lock-icon {
  font-size: var(--fs-tiny);
  color: var(--color-text-light);
}

.article-preview {
  background: var(--color-card-bg);
  padding: 3rem;
  border: 1px solid var(--color-border-light);
  min-height: 400px;
}

.article-meta {
  color: var(--color-text-light);
  font-size: var(--fs-tiny);
  margin-bottom: 1rem;
  letter-spacing: 0.5px;
}

.article-title {
  font-size: var(--fs-h1);
  font-weight: 600;
  margin-bottom: 1.5rem;
  color: var(--color-text-dark);
  line-height: 1.4;
}

.article-intro {
  font-size: var(--fs-body);
  color: var(--color-text-gray);
  margin-bottom: 2rem;
  line-height: 1.8;
}

.article-quote {
  background-color: var(--color-quote-bg);
  border-left: 3px solid var(--color-brand-red);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  color: var(--color-text-gray);
  font-size: var(--fs-small);
  line-height: 1.8;
  font-style: italic;
}

.article-points {
  margin-top: 2rem;
}

.article-points h3 {
  font-size: var(--fs-h2);
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--color-text-dark);
}

.article-points p {
  color: var(--color-text-gray);
  line-height: 1.8;
  font-size: var(--fs-body);
  margin-bottom: 1rem;
}

/* ===== 文章阅读页 ===== */
.article-container {
  max-width: 1100px;
  margin: 3rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 4rem;
  align-items: start;
}

.article-nav {
  position: sticky;
  top: 80px;
}

.article-nav-title {
  font-size: var(--fs-tiny);
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 1rem;
  font-weight: 600;
}

.article-content {
  background: var(--color-card-bg);
  padding: 3rem 4rem;
  border: 1px solid var(--color-border-light);
  max-width: 780px;
}

.article-header {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--color-border-main);
  padding-bottom: 2rem;
}

.article-content h1 {
  font-size: var(--fs-h1);
  font-weight: 600;
  margin-bottom: 1rem;
  line-height: 1.4;
  color: var(--color-text-dark);
}

.article-byline {
  color: var(--color-text-light);
  font-size: var(--fs-small);
}

.article-body {
  font-size: var(--fs-body);
  line-height: 1.9;
  color: var(--color-text-dark);
}

.article-body p {
  margin-bottom: 1.5rem;
}

.article-body h2 {
  font-size: var(--fs-h2);
  font-weight: 600;
  margin: 3rem 0 1rem;
  color: var(--color-text-dark);
}

.article-body h3 {
  font-size: var(--fs-body);
  font-weight: 600;
  margin: 2rem 0 0.75rem;
  color: var(--color-text-dark);
}

.article-body strong {
  font-weight: 600;
}

.article-body blockquote {
  background-color: var(--color-quote-bg);
  border-left: 3px solid var(--color-brand-red);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--color-text-gray);
  font-size: var(--fs-small);
  line-height: 1.8;
}

.article-footer {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border-main);
}

.next-article {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-brand-red);
  text-decoration: none;
  font-size: var(--fs-small);
  font-weight: 500;
  transition: gap 0.2s ease;
}

.next-article:hover {
  gap: 0.75rem;
}

/* ===== 登录页 ===== */
.login-container {
  max-width: 420px;
  margin: 5rem auto;
  padding: 0 2rem;
}

.login-box {
  background: var(--color-card-bg);
  padding: 2.5rem;
  border: 1px solid var(--color-border-light);
}

.login-box h1 {
  font-size: var(--fs-h1);
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text-dark);
}

.login-box p {
  color: var(--color-text-gray);
  margin-bottom: 2rem;
  font-size: var(--fs-small);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.4rem;
  color: var(--color-text-dark);
  font-size: var(--fs-small);
  font-weight: 500;
}

.form-group input {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--color-border-main);
  border-radius: 3px;
  font-size: var(--fs-body);
  font-family: var(--font-stack);
  background-color: var(--color-bg-warm);
  transition: border-color 0.2s ease;
}

.form-group input:focus {
  outline: none;
  border-color: var(--color-brand-red);
}

.submit-button {
  width: 100%;
  padding: 0.75rem;
  background-color: var(--color-brand-red);
  color: white;
  border: none;
  border-radius: 3px;
  font-size: var(--fs-body);
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.submit-button:hover {
  background-color: var(--color-brand-red-hover);
}

.pricing-section {
  margin-top: 4rem;
}

.pricing-section h2 {
  font-size: var(--fs-h2);
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
  color: var(--color-text-dark);
}

.pricing-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.pricing-card {
  background: var(--color-card-bg);
  padding: 1.5rem;
  border: 1px solid var(--color-border-main);
  text-align: center;
}

.pricing-card.featured {
  border: 2px solid var(--color-brand-red);
}

.pricing-card h3 {
  font-size: var(--fs-body);
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--color-text-dark);
}

.pricing-card .price {
  font-size: var(--fs-h1);
  font-weight: 600;
  color: var(--color-brand-red);
  margin-bottom: 0.25rem;
}

.pricing-card .period {
  color: var(--color-text-light);
  font-size: var(--fs-small);
  margin-bottom: 1.25rem;
}

.pricing-card ul {
  list-style: none;
  margin-bottom: 1.5rem;
  text-align: left;
}

.pricing-card li {
  padding: 0.35rem 0;
  color: var(--color-text-gray);
  font-size: var(--fs-small);
}

.pricing-card li::before {
  content: "✓ ";
  color: var(--color-brand-red);
  font-weight: bold;
  margin-right: 0.25rem;
}

/* ===== 页脚 ===== */
.footer {
  max-width: 1100px;
  margin: 6rem auto 2rem;
  padding: 2rem;
  text-align: center;
  color: var(--color-text-light);
  font-size: var(--fs-small);
  border-top: 1px solid var(--color-border-main);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .catalog-container,
  .article-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .toc-sidebar,
  .article-nav {
    position: static;
  }
}

@media (max-width: 768px) {
  .hero {
    padding: 6rem 1.5rem 3rem;
  }

  .hero-title {
    font-size: 1.75rem;
  }
  
  .article-content,
  .article-preview {
    padding: 1.5rem;
  }
  
  .navbar-container {
    padding: 0 1rem;
  }
}