/* Physique-Chimie AI Maroc — Styles globaux */
:root {
  --color-primary: #1e6091;
  --color-primary-dark: #14486b;
  --color-secondary: #2a9d8f;
  --color-accent: #e76f51;
  --color-bg: #f4f7fa;
  --color-surface: #ffffff;
  --color-text: #1c2b36;
  --color-muted: #6b7c88;
  --color-border: #dfe7ec;
  --color-success: #2a9d5c;
  --color-error: #d64550;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(20, 40, 60, 0.06);
  --font-ar: 'Tahoma', 'Segoe UI', sans-serif;
  --font-fr: 'Segoe UI', 'Inter', sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-ar);
  line-height: 1.6;
}
body.dir-ltr { font-family: var(--font-fr); }

a { color: var(--color-primary); text-decoration: none; }
h1, h2, h3 { margin: 0 0 0.5em; }

.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 15px;
  font-weight: 600;
  transition: transform 0.1s ease, opacity 0.2s ease;
}
.btn:active { transform: scale(0.98); }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-outline { background: transparent; border: 1px solid var(--color-border); color: var(--color-text); }
.btn-ghost { background: transparent; color: var(--color-primary); }
.btn-danger { background: var(--color-error); color: #fff; }
.btn-block { width: 100%; }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-lg { padding: 14px 28px; font-size: 17px; }
.btn:disabled { opacity: 0.6; cursor: not-allowed; }

/* ---------- Landing page ---------- */
.landing-nav {
  display: flex; justify-content: space-between; align-items: center;
  padding: 20px 40px; background: var(--color-surface); box-shadow: var(--shadow);
}
.brand { font-weight: 700; font-size: 20px; color: var(--color-primary-dark); }
.nav-actions { display: flex; gap: 10px; }

.hero {
  text-align: center;
  padding: 80px 20px 60px;
  background: linear-gradient(160deg, #eaf3f8 0%, #f4f7fa 100%);
}
.hero h1 { font-size: 36px; color: var(--color-primary-dark); }
.hero p { max-width: 620px; margin: 16px auto 30px; color: var(--color-muted); font-size: 17px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.features {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px; padding: 50px 40px; max-width: 1100px; margin: 0 auto;
}
.feature-card {
  background: var(--color-surface); border-radius: var(--radius); padding: 26px;
  box-shadow: var(--shadow); text-align: center;
}
.feature-card .icon { font-size: 34px; margin-bottom: 10px; }

/* ---------- Auth pages ---------- */
.auth-page { display: flex; min-height: 100vh; align-items: center; justify-content: center; padding: 20px; }
.auth-card {
  background: var(--color-surface); padding: 36px; border-radius: var(--radius);
  box-shadow: var(--shadow); width: 100%; max-width: 420px;
}
.auth-card h1 { text-align: center; font-size: 20px; color: var(--color-primary-dark); }
.auth-card h2 { text-align: center; font-size: 16px; color: var(--color-muted); font-weight: 500; margin-bottom: 24px; }
.auth-card label { display: block; margin-bottom: 16px; font-size: 14px; font-weight: 600; }
.auth-card input, .auth-card select {
  width: 100%; padding: 10px 12px; margin-top: 6px; border-radius: 8px;
  border: 1px solid var(--color-border); font-size: 15px; font-family: inherit;
}
.auth-switch { text-align: center; margin-top: 16px; font-size: 14px; color: var(--color-muted); }

.alert { padding: 12px 16px; border-radius: 8px; margin-bottom: 16px; font-size: 14px; }
.alert-error { background: #fdecec; color: var(--color-error); }
.alert-success { background: #e8f7ee; color: var(--color-success); }
.alert-info { background: #eaf3f8; color: var(--color-primary-dark); }

.text-muted { color: var(--color-muted); }
.text-error { color: var(--color-error); }
.text-center { text-align: center; }

.pcai-footer { text-align: center; padding: 24px; color: var(--color-muted); font-size: 13px; }