/* ── Google Font ─────────────────────────────── */
@import url("https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swap");

/* ── Design tokens ───────────────────────────── */
:root {
  --bright-snow:    #f8f9faff;
  --platinum:       #e9ecefff;
  --alabaster-grey: #dee2e6ff;
  --pale-slate:     #ced4daff;
  --pale-slate-2:   #adb5bdff;
  --slate-grey:     #6c757dff;
  --iron-grey:      #495057ff;
  --gunmetal:       #343a40ff;
  --carbon-black:   #212529ff;

  --font-base: "Open Sans", sans-serif;
  --radius: 8px;
}

/* ── Reset & base ────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Open Sans", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  background: var(--platinum);
  color: var(--carbon-black);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4 {
  font-family: "Open Sans", sans-serif;
  font-weight: 700;
  color: var(--carbon-black);
}

/* ── Navbar ──────────────────────────────────── */
.navbar {
  background: var(--gunmetal);
  padding: 0.9rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar .brand {
  color: var(--bright-snow);
  font-size: 1.3rem;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 0.02em;
}

.nav-links { list-style: none; display: flex; gap: 1.5rem; }

.nav-links a {
  color: var(--pale-slate-2);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 600;
  transition: color .2s;
}

.nav-links a:hover { color: var(--bright-snow); }

/* ── Container ───────────────────────────────── */
.container {
  max-width: 860px;
  margin: 2.5rem auto;
  padding: 0 1.5rem;
  flex: 1;
}

/* ── Alerts ──────────────────────────────────── */
.alert {
  padding: 0.85rem 1.2rem;
  border-radius: var(--radius);
  margin-bottom: 1.2rem;
  font-size: 0.95rem;
  font-weight: 500;
}

.alert-info {
  background: var(--platinum);
  border: 1px solid var(--pale-slate);
  color: var(--iron-grey);
}

.alert-success {
  background: #d1e7dd;
  border: 1px solid #a3cfbb;
  color: #0f5132;
}

.alert-danger {
  background: #f8d7da;
  border: 1px solid #f1aeb5;
  color: #842029;
}

/* ── Hero ────────────────────────────────────── */
.hero {
  text-align: center;
  padding: 5rem 1rem;
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--carbon-black);
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.1rem;
  color: var(--slate-grey);
  max-width: 540px;
  margin-inline: auto;
  margin-bottom: 2rem;
}

/* ── Button ──────────────────────────────────── */
.btn {
  display: inline-block;
  padding: 0.7rem 1.7rem;
  background: var(--iron-grey);
  color: var(--bright-snow);
  border: none;
  border-radius: var(--radius);
  font-family: "Open Sans", sans-serif;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background .2s, transform .1s;
}

.btn:hover {
  background: var(--carbon-black);
  transform: translateY(-1px);
}

.btn:active { transform: translateY(0); }

/* ── About section ───────────────────────────── */
section {
  background: var(--bright-snow);
  border-radius: var(--radius);
  padding: 2rem 2.2rem;
  box-shadow: 0 2px 10px rgba(33, 37, 41, 0.08);
}

section h1 { margin-bottom: 1rem; }

section ul {
  padding-left: 1.4rem;
  line-height: 2.2;
  color: var(--iron-grey);
}

section ul li::marker { color: var(--slate-grey); }

code {
  background: var(--alabaster-grey);
  color: var(--gunmetal);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  font-size: 0.88em;
}

/* ── Login form ──────────────────────────────── */
.form-container {
  max-width: 440px;
  margin: 0 auto;
  background: var(--bright-snow);
  border-radius: var(--radius);
  padding: 2.4rem 2.2rem;
  box-shadow: 0 2px 10px rgba(33, 37, 41, 0.1);
}

.form-container h1 { margin-bottom: 1.6rem; }

.form-group { margin-bottom: 1.2rem; }

.form-group label {
  display: block;
  margin-bottom: 0.45rem;
  font-family: "Open Sans", sans-serif;
  font-weight: 600;
  font-size: 0.88rem;
  color: var(--iron-grey);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.form-group input {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1.5px solid var(--pale-slate);
  border-radius: var(--radius);
  font-family: "Open Sans", sans-serif;
  font-size: 1rem;
  color: var(--carbon-black);
  background: var(--bright-snow);
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}

.form-group input:focus {
  border-color: var(--slate-grey);
  box-shadow: 0 0 0 3px rgba(108, 117, 125, 0.2);
}

.form-group input::placeholder { color: var(--pale-slate-2); }

.form-container .btn { width: 100%; margin-top: 0.6rem; }

/* ── Footer ──────────────────────────────────── */
.footer {
  text-align: center;
  padding: 1.2rem;
  font-size: 0.85rem;
  color: var(--slate-grey);
  border-top: 1px solid var(--alabaster-grey);
  background: var(--bright-snow);
}