:root {
    --color-primary: #1E3A5F;
    --color-accent: #2D7DD2;
    --color-bg: #F4F6F9;
    --color-card: #ffffff;
    --color-text: #1E293B;
    --color-muted: #64748B;
    --color-border: #E2E8F0;
    --color-success-bg: rgba(22, 163, 74, .12);
    --color-success: #16A34A;
    --color-error-bg: rgba(220, 38, 38, .12);
    --color-error: #DC2626;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Inter', sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
}

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* --- Login --- */

.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.auth-card {
    background: var(--color-card);
    border-radius: 12px;
    box-shadow: 0 4px 24px rgba(15, 23, 42, .08);
    padding: 32px 28px;
    width: 100%;
    max-width: 380px;
}

.auth-card .brand {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

.auth-card .brand span {
    font-weight: 700;
    font-size: 16px;
    color: var(--color-primary);
}

.auth-card h1 {
    font-size: 19px;
    margin: 0 0 18px;
    color: var(--color-primary);
}

.form-group { margin-bottom: 14px; }

label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--color-text);
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="date"],
input[type="time"],
textarea,
select {
    width: 100%;
    padding: 9px 10px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    font-family: inherit;
    font-size: 14px;
    background: #fff;
    color: var(--color-text);
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--color-accent);
}

button.btn-primary {
    background: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
}

.auth-card button.btn-primary { width: 100%; margin-top: 4px; }

button.btn-primary:disabled { opacity: .6; cursor: default; }

button.btn-secondary {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text);
    border-radius: 6px;
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
}

.msg {
    font-size: 13px;
    padding: 10px 12px;
    border-radius: 6px;
    margin-bottom: 14px;
    display: none;
}

.msg-success { background: var(--color-success-bg); color: var(--color-success); }
.msg-error { background: var(--color-error-bg); color: var(--color-error); }

/* --- Layout autenticado --- */

.app-header {
    background: var(--color-card);
    border-bottom: 1px solid var(--color-border);
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.app-header .brand span {
    font-weight: 700;
    font-size: 15px;
    color: var(--color-primary);
}

.app-header nav {
    display: flex;
    align-items: center;
    gap: 18px;
    font-size: 14px;
}

.app-header .logout-link {
    color: var(--color-muted);
    cursor: pointer;
}

.app-main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 32px 24px;
}

.app-main h1 {
    color: var(--color-primary);
    font-size: 22px;
    margin: 0 0 24px;
}

.empty-state {
    color: var(--color-muted);
    font-size: 14px;
    text-align: center;
    padding: 40px 0;
}

.back-link { margin-bottom: 16px; font-size: 14px; }

/* --- Lista de cursos --- */

.course-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.course-row {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 16px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    cursor: pointer;
    transition: box-shadow .15s ease;
}

.course-row:hover { box-shadow: 0 2px 10px rgba(15, 23, 42, .08); }

.course-row-title { font-weight: 600; font-size: 14px; }

.course-row-meta {
    display: flex;
    gap: 16px;
    font-size: 13px;
    color: var(--color-muted);
    flex-shrink: 0;
}

/* --- Detalle de curso / asistencia --- */

.course-header-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 20px 24px;
    margin-bottom: 20px;
}

.course-header-card h1 { margin: 0 0 12px; font-size: 19px; }

.course-header-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 12px;
    font-size: 13px;
}

.course-header-grid dt { color: var(--color-muted); margin: 0 0 2px; }
.course-header-grid dd { margin: 0; font-weight: 600; }

.students-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 20px 24px;
}

.students-card h2 { margin: 0 0 16px; font-size: 16px; color: var(--color-primary); }

.student-block {
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 16px;
    margin-bottom: 14px;
}

.student-block-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 12px;
}

.student-block-name { font-weight: 700; font-size: 15px; }

.student-block-meta {
    font-size: 12px;
    color: var(--color-muted);
    margin-top: 2px;
    display: flex;
    flex-wrap: wrap;
    gap: 4px 12px;
}

.student-block-flags {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 13px;
}

.student-block-flags label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    font-weight: 400;
    margin: 0;
    white-space: nowrap;
}

.student-block-flags input[type="checkbox"] { width: auto; }

.student-block-flags .flag-readonly { color: var(--color-muted); }

.attendance-grid-wrapper { overflow-x: auto; }

.attendance-grid {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}

.attendance-grid th, .attendance-grid td {
    border: 1px solid var(--color-border);
    padding: 8px;
    text-align: left;
    vertical-align: top;
}

.attendance-grid th {
    background: var(--color-bg);
    font-size: 12px;
    color: var(--color-muted);
    white-space: nowrap;
}

.attendance-grid td.attendance-check-cell { text-align: center; white-space: nowrap; }
.attendance-grid textarea { min-width: 160px; min-height: 40px; font-size: 12px; }

.save-bar {
    position: sticky;
    bottom: 0;
    background: var(--color-card);
    border-top: 1px solid var(--color-border);
    padding: 14px 24px;
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 20px;
}

@media (max-width: 700px) {
    .app-header nav { gap: 10px; font-size: 13px; }
    .app-main { padding: 20px 14px; }
    .course-row { flex-direction: column; align-items: flex-start; }
}