:root {
    --navy: #142E4C;
    --sky: #1D6FA5;
    --sky-light: #E7F1F8;
    --bg: #F5F7FA;
    --surface: #FFFFFF;
    --border: #DCE3EA;
    --text: #1D2733;
    --text-muted: #5B6B7A;
    --amber: #D98E2C;
    --green: #2E8B57;
    --red: #C0392B;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(20,46,76,0.08), 0 1px 2px rgba(20,46,76,0.06);
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

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

/* ---------- Topbar ---------- */
.topbar {
    background: var(--navy);
    color: #fff;
}
.topbar-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}
.brand {
    color: #fff;
    font-weight: 700;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}
.brand:hover { text-decoration: none; }
.brand-mark {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid #fff;
    position: relative;
    flex-shrink: 0;
}
.brand-mark::before, .brand-mark::after {
    content: "";
    position: absolute;
    background: #fff;
}
.brand-mark::before { width: 2px; height: 10px; top: 3px; left: 8px; }
.brand-mark::after { width: 10px; height: 2px; top: 8px; left: 3px; }

.main-nav { display: flex; align-items: center; gap: 20px; font-size: 0.92rem; }
.main-nav a { color: #cfe0ee; }
.main-nav a:hover { color: #fff; }
.nav-user { color: #8fa8bd; font-size: 0.85rem; }
.nav-logout {
    background: rgba(255,255,255,0.12);
    padding: 6px 12px;
    border-radius: var(--radius);
    color: #fff !important;
}

/* ---------- Layout ---------- */
.page {
    max-width: 1100px;
    margin: 0 auto;
    padding: 32px 24px 64px;
}
.page-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 12px;
}
h1 { font-size: 1.6rem; margin: 0; color: var(--navy); }
h2 { font-size: 1.15rem; color: var(--navy); margin: 0 0 12px; }
h3 { font-size: 1rem; color: var(--navy); margin: 0 0 8px; }

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 20px;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-block;
    padding: 9px 16px;
    border-radius: var(--radius);
    border: 1px solid transparent;
    background: var(--sky);
    color: #fff;
    font-size: 0.9rem;
    cursor: pointer;
    font-weight: 600;
}
.btn:hover { background: #175b87; text-decoration: none; color: #fff; }
.btn-secondary { background: #fff; color: var(--sky); border-color: var(--sky); }
.btn-secondary:hover { background: var(--sky-light); color: var(--sky); }
.btn-danger { background: var(--red); }
.btn-danger:hover { background: #97281c; }
.btn-sm { padding: 5px 10px; font-size: 0.8rem; }

/* ---------- Forms ---------- */
label { display: block; font-weight: 600; font-size: 0.85rem; margin-bottom: 5px; color: var(--navy); }
input[type=text], input[type=date], input[type=number], input[type=password],
select, textarea {
    width: 100%;
    padding: 9px 11px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.92rem;
    font-family: inherit;
    background: #fff;
    color: var(--text);
}
textarea { resize: vertical; min-height: 70px; }
input:disabled, textarea:disabled { background: #F0F2F5; color: var(--text-muted); }
.form-row { margin-bottom: 16px; }
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
}
.form-actions { margin-top: 20px; display: flex; gap: 10px; }

/* ---------- Tables ---------- */
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); font-size: 0.9rem; }
th { color: var(--text-muted); font-weight: 600; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.03em; }
tr:hover td { background: var(--sky-light); }

/* ---------- Badges ---------- */
.badge {
    display: inline-block;
    padding: 3px 9px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}
.badge-instructor { background: #FCEBD3; color: var(--amber); }
.badge-student { background: var(--sky-light); color: var(--sky); }

/* ---------- Logbook page ---------- */
.mission-doc {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--surface);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}
.mission-doc-header {
    display: grid;
    grid-template-columns: 140px 1fr;
}
.mission-doc-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    border-right: 1px solid var(--border);
    padding: 10px;
}
.mission-doc-title {
    padding: 16px 20px;
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--navy);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
}
.mission-doc-fields {
    display: grid;
    grid-template-columns: 1fr 1fr;
}
.mission-doc-fields .field-cell {
    padding: 10px 20px;
    border-bottom: 1px solid var(--border);
}
.mission-doc-fields .field-cell:first-child { border-right: 1px solid var(--border); }
.mission-doc-fields .field-cell label {
    margin-bottom: 4px;
}
.mission-doc-fields .mission-name {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--navy);
    text-align: right;
    display: block;
    padding-top: 4px;
}

.section-bar {
    background: #6B7684;
    color: #fff;
    text-align: center;
    font-weight: 700;
    padding: 10px;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
}
.section-body { padding: 18px 20px; }
.fixed-text { color: var(--text); font-size: 0.92rem; line-height: 1.6; }
.section-subheader {
    background: #E3E7EB;
    padding: 8px 20px;
    font-weight: 700;
    color: var(--navy);
    font-size: 0.85rem;
}

.task-list { padding: 4px 20px 14px; }
.task-row-doc {
    display: grid;
    grid-template-columns: 28px 1fr 1fr;
    gap: 12px;
    align-items: center;
    padding: 9px 0;
    border-bottom: 1px solid #EEF1F4;
}
.task-row-doc:last-child { border-bottom: none; }
.task-row-doc input[type=checkbox] { width: 19px; height: 19px; accent-color: var(--sky); }
.task-row-doc .task-label { font-size: 0.92rem; }
.task-row-doc input[type=text] { font-size: 0.85rem; padding: 6px 9px; }
.task-list-headings {
    display: grid;
    grid-template-columns: 28px 1fr 1fr;
    gap: 12px;
    padding: 0 20px 6px;
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    color: var(--text-muted);
    border-bottom: 2px solid var(--border);
    margin: 0 0 4px;
}

.notes-block textarea {
    min-height: 90px;
}

.doc-footer-table {
    display: grid;
    grid-template-columns: 1fr 1fr;
}
.doc-footer-table .cell-pair { display: grid; grid-template-columns: 130px 1fr; border-bottom: 1px solid var(--border); }
.doc-footer-table .cell-pair:last-child { border-bottom: none; }
.doc-footer-table .cell-pair:first-child { border-right: 1px solid var(--border); }
.doc-footer-table .cell-label {
    background: #6B7684;
    color: #fff;
    font-weight: 700;
    font-size: 0.82rem;
    padding: 10px 14px;
    display: flex;
    align-items: center;
}
.doc-footer-table .cell-value { padding: 6px 10px; display: flex; align-items: center; }
.doc-footer-table .cell-value input {
    border: none;
    background: transparent;
    padding: 6px;
}
.doc-footer-table .cell-value input:disabled { background: transparent; color: var(--text); }



.alert { padding: 12px 16px; border-radius: var(--radius); margin-bottom: 18px; font-size: 0.9rem; }
.alert-error { background: #FBEAE8; color: var(--red); border: 1px solid #F1C4BE; }
.alert-success { background: #E9F5EE; color: var(--green); border: 1px solid #BEE3CD; }

.empty-state {
    text-align: center;
    padding: 48px 20px;
    color: var(--text-muted);
}