/* ===== RESET & BASE ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: #26272a; line-height: 1.6; background: #fff;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== COLOR VARIABLES (秒达云风格) ===== */
:root {
  --primary: #FA5252;
  --primary-dark: #d63030;
  --primary-light: #fef6f9;
  --accent: #FA5252;
  --text-dark: #26272a;
  --text-mid: #555c6a;
  --text-light: #737e97;
  --bg-gray: #f5f7fa;
  --bg-warm: #fef9f9;
  --white: #ffffff;
  --border: #e9f0fc;
  --gradient-primary: #FA5252;
  --gradient-hero: linear-gradient(135deg, #fff5f5 0%, #fef4f4 50%, #f5f7fa 100%);
  --shadow-card: 0 2px 8px rgba(238,80,80,.06);
  --shadow-hover: 0 8px 24px rgba(238,80,80,.12);
  --success: #00c853;
  --warning: #ff9800;
  --error: #FA5252;
  --code-bg: #1a1a2e;
  --code-text: #e9f0fc;
}

/* ===== UTILITY ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

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

.gradient-text {
  color: var(--primary);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; border-radius: 100px; font-size: 15px;
  font-weight: 600; cursor: pointer; border: none; transition: all .25s ease;
}
.btn-primary {
  background: var(--gradient-primary); color: #fff;
  box-shadow: 0 4px 12px rgba(238,80,80,.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(238,80,80,.35); }
.btn-outline {
  background: transparent; color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-outline:hover { background: var(--primary-light); }
.btn-white {
  background: #fff; color: var(--primary); font-weight: 700;
}
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,.15); }
.login-btn { padding:8px 16px; }
.register-btn { padding:8px 20px; }
.login-btn, .register-btn { font-size:14px; }

/* ===== FOOTER ===== */
.footer { background: #1a1a2e; color: rgba(255,255,255,.7); padding: 64px 0 32px; }
.footer-grid { display: grid; grid-template-columns: 2fr repeat(4, 1fr); gap: 40px; margin-bottom: 48px; }
.footer-brand .logo { font-size: 20px; font-weight: 700; color: #fff; margin-bottom: 12px; }
.footer-brand p { font-size: 14px; line-height: 1.7; max-width: 280px; margin-bottom: 16px; }
.footer-brand .social { display: flex; gap: 12px; align-items: center; }
.footer-brand .social a { display: flex; align-items: center; justify-content: center; width: 32px; height: 32px; border-radius: 6px; background: rgba(255,255,255,.06); color: rgba(255,255,255,.5); transition: all .2s; }
.footer-brand .social a:hover { color: var(--primary); background: rgba(250,82,82,.15); }
.footer-brand .social a svg { width: 18px; height: 18px; }
.footer-col h4 { color: #fff; font-size: 14px; font-weight: 600; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; padding: 5px 0; transition: color .2s; }
.footer-col a:hover { color: var(--primary); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding-top: 24px; display: flex; justify-content: space-between; align-items: center; font-size: 13px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 835px) {
  .container { padding: 0 12px; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  html { font-size: 14px; }
  .container { padding: 0 16px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer { padding: 40px 0 24px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
  .footer-brand .social { justify-content: center; }
  .btn { padding: 10px 20px; font-size: 14px; }
}

/* ===== TABLE WRAPPER for mobile ===== */
@media (max-width: 768px) {
  table { display: block; overflow-x: auto; white-space: nowrap; -webkit-overflow-scrolling: touch; }
}