:root {
    --primary: #1a5276;
    --primary-light: #2e86c1;
    --bg: #f4f6f7;
    --card-bg: #ffffff;
    --border: #d5dbdb;
    --text: #2c3e50;
    --ok: #27ae60;
    --fail: #c0392b;
    --warn: #f39c12;
    --muted: #7f8c8d;
}

* { box-sizing: border-box; }

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

.top-navbar {
    background: #1c1c1c;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: .5rem 1.5rem;
    flex-wrap: wrap;
    gap: .5rem;
}
.navbar-brand {
    display: flex;
    align-items: center;
    gap: .6rem;
    color: #fff;
    text-decoration: none;
    font-weight: bold;
    font-size: .95rem;
}
.navbar-brand img { display: block; }
.navbar-links { display: flex; gap: .4rem; }
.navbar-links a {
    color: #d5dbdb;
    text-decoration: none;
    padding: .5rem .9rem;
    border-radius: 4px;
    font-size: .85rem;
    border: 1px solid transparent;
    transition: background .15s, color .15s;
}
.navbar-links a:hover { background: rgba(255,255,255,.08); color: #fff; }
.navbar-links a.active {
    background: var(--primary-light);
    color: #fff;
    font-weight: bold;
}
.navbar-user {
    color: #9fb0be;
    font-size: .8rem;
    padding: .5rem .4rem;
    align-self: center;
}

/* Login: mismos tokens/componentes que el resto del sistema
   (.top-navbar, .card, .btn, patrón de campos de .filters-row),
   solo centrado en pantalla completa. */
.login-body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-family: Arial, Helvetica, sans-serif;
    color: var(--text);
    background: var(--bg);
}
.login-main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    box-sizing: border-box;
}
.login-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 2rem;
    width: 100%;
    max-width: 360px;
    box-sizing: border-box;
    text-align: center;
}
.login-logo { display: block; margin: 0 auto 1rem; }
.login-card h1 { font-size: 1.2rem; margin: 0 0 .3rem; color: var(--text); }
.login-card .subtitle { font-size: .85rem; color: var(--muted); margin: 0 0 1.5rem; }
.login-card form { text-align: left; display: flex; flex-direction: column; gap: 1rem; }
.login-card .field { display: flex; flex-direction: column; gap: .3rem; }
.login-card label { font-size: .8rem; font-weight: bold; color: var(--muted); }
.login-card input {
    padding: .6rem .7rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: .95rem;
    width: 100%;
    box-sizing: border-box;
    font-family: inherit;
    transition: border-color .15s, box-shadow .15s;
}
.login-card input:focus {
    outline: none;
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(46,134,193,.2);
}
.login-card input:disabled { background: var(--bg); color: var(--muted); cursor: not-allowed; }
.login-card .btn {
    margin-top: .3rem;
    padding: .65rem;
    font-size: .95rem;
    width: 100%;
}
.login-card .btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}
.login-error {
    background: #fdecea;
    color: var(--fail);
    border: 1px solid #f5c6cb;
    border-radius: 4px;
    padding: .6rem .8rem;
    font-size: .85rem;
    margin-bottom: 1.2rem;
    text-align: left;
}
.login-error::before { content: "⚠ "; }

@media (max-width: 480px) {
    .login-card { padding: 1.5rem 1.25rem; }
    .login-card input, .login-card .btn { font-size: 1rem; padding: .7rem .75rem; }
}

.app-header {
    background: var(--primary);
    color: #fff;
    padding: 1.2rem 2rem;
}
.app-header h1 { margin: 0; font-size: 1.4rem; }
.app-header .subtitle { margin: .2rem 0 0; font-size: .85rem; opacity: .85; }

.app-main { padding: 1.5rem 2rem; max-width: 1200px; margin: 0 auto; }

.filters-card, .card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 1.2rem;
    margin-bottom: 1.2rem;
}

.filters-row { display: flex; flex-wrap: wrap; gap: 1rem; align-items: flex-end; }
.filters-row .field { display: flex; flex-direction: column; gap: .3rem; }
.filters-row label { font-size: .8rem; font-weight: bold; color: var(--muted); }
.filters-row select, .filters-row input {
    padding: .45rem .6rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: .9rem;
    min-width: 220px;
}
#course-select { min-height: 120px; }

.btn {
    background: var(--primary-light);
    color: #fff;
    border: none;
    padding: .55rem 1.1rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: .9rem;
}
.btn:hover { background: var(--primary); }
.btn.secondary { background: var(--muted); }
.btn.btn-small { padding: .3rem .65rem; font-size: .8rem; }
.btn.btn-danger { background: #c0392b; }
.btn.btn-danger:hover { background: #922b21; }
.btn:disabled { opacity: .6; cursor: not-allowed; }

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, .55);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    z-index: 9999;
}
.modal-box {
    background: #fff;
    border-radius: 10px;
    width: 100%;
    max-width: 440px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, .25);
    padding: 1.5rem 1.6rem;
    border-top: 4px solid var(--primary, #3b6fa8);
    animation: modal-pop .15s ease-out;
}
.modal-box.danger { border-top-color: #c0392b; }
.modal-box h3 {
    margin: 0 0 .75rem;
    font-size: 1.1rem;
    color: var(--text, #1f2937);
}
.modal-box.danger h3 { color: #c0392b; }
.modal-box p {
    margin: 0 0 1.4rem;
    white-space: pre-line;
    color: var(--text, #374151);
    line-height: 1.5;
    font-size: .92rem;
}
.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: .6rem;
}
@keyframes modal-pop {
    from { opacity: 0; transform: scale(.96); }
    to   { opacity: 1; transform: scale(1); }
}
@media (max-width: 480px) {
    .modal-box { padding: 1.25rem; }
    .modal-actions { flex-direction: column-reverse; }
    .modal-actions .btn { width: 100%; }
}

.tabs { display: flex; gap: .3rem; border-bottom: 2px solid var(--border); margin-bottom: 1rem; }
.tab-btn {
    background: none; border: none; padding: .6rem 1rem; cursor: pointer;
    font-size: .9rem; color: var(--muted); border-bottom: 3px solid transparent;
}
.tab-btn.active { color: var(--primary); border-color: var(--primary-light); font-weight: bold; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem; margin-bottom: 1rem; }
.stat-tile { background: var(--card-bg); border: 1px solid var(--border); border-radius: 6px; padding: 1rem; text-align: center; }
.stat-tile .value { font-size: 1.6rem; font-weight: bold; }
.stat-tile .label { font-size: .75rem; color: var(--muted); text-transform: uppercase; }
.stat-tile.ok .value { color: var(--ok); }
.stat-tile.fail .value { color: var(--fail); }
.stat-tile.warn .value { color: var(--warn); }
.stat-tile.muted .value { color: var(--muted); }

table.dataTable { width: 100% !important; font-size: .85rem; }
.badge { padding: .15rem .5rem; border-radius: 3px; font-size: .75rem; color: #fff; }
.badge.Aprobado { background: var(--ok); }
.badge.Reprobado { background: var(--fail); }
.badge.En.proceso, .badge.EnProceso { background: var(--warn); }
.badge.No.iniciado, .badge.NoIniciado { background: var(--muted); }

.status-msg { padding: 1rem; text-align: center; color: var(--muted); }

.chart-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}
.chart-grid-wide { grid-template-columns: repeat(auto-fit, minmax(420px, 1fr)); }
.chart-card { padding: 1rem; }
.chart-card h3 { margin: 0 0 .75rem; font-size: .95rem; }
.chart-card canvas { max-height: 260px; }

.app-footer { text-align: center; padding: 1rem; color: var(--muted); font-size: .8rem; }
.app-footer .copyright { font-size: .7rem; opacity: .75; margin-top: .4rem; line-height: 1.4; }