/* =====================================================================
   Campus Organizer — Design tokens & signature elements
   Theme: "student planner / notebook" — warm paper surfaces, an ink-navy
   primary, an ochre "highlighter" accent for anything time-sensitive,
   and a sage green for completion. Countdown badges are styled like a
   library due-date stamp; the sidebar reads like a notebook spine.
   ===================================================================== */

:root {
    --bg:            #FAF8F4;
    --surface:       #FFFFFF;
    --surface-2:     #F2EFE8;
    --ink:           #20222B;
    --ink-muted:     #6F6C63;
    --border:        #E4E1D9;

    --primary:       #2B3A67;
    --primary-light: #47588F;
    --accent:        #C08A2E;   /* ochre "highlighter" — urgency, countdowns */
    --success:       #3E7C59;
    --danger:        #B8503F;

    --font-display: 'Fraunces', ui-serif, Georgia, serif;
    --font-body:    'Inter', ui-sans-serif, system-ui, sans-serif;
    --font-mono:    'JetBrains Mono', ui-monospace, 'SFMono-Regular', monospace;
}

html.dark {
    --bg:            #14161B;
    --surface:       #1C1F26;
    --surface-2:     #23262E;
    --ink:           #E9E7E1;
    --ink-muted:     #9B988E;
    --border:        #2B2E36;

    --primary:       #7E8FC4;
    --primary-light: #A2AFDA;
    --accent:        #E0A94E;
    --success:       #62B98A;
    --danger:        #E08370;
}

body {
    background-color: var(--bg);
    color: var(--ink);
    font-family: var(--font-body);
}

.font-display { font-family: var(--font-display); }
.font-mono    { font-family: var(--font-mono); }

/* --- Sidebar: "notebook spine" ---------------------------------------- */
.spine {
    background-color: var(--surface);
    border-right: 1px solid var(--border);
    position: relative;
}
.spine::before {
    content: "";
    position: absolute;
    top: 0; bottom: 0; left: 0;
    width: 4px;
    background: repeating-linear-gradient(
        to bottom,
        var(--primary) 0px, var(--primary) 10px,
        transparent 10px, transparent 20px
    );
    opacity: 0.35;
}

.nav-tab {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    padding: 0.55rem 0.9rem;
    border-radius: 0.6rem;
    color: var(--ink-muted);
    font-size: 0.875rem;
    font-weight: 500;
    transition: background-color 0.15s ease, color 0.15s ease;
}
.nav-tab:hover {
    background-color: var(--surface-2);
    color: var(--ink);
}
.nav-tab.active {
    background-color: var(--primary);
    color: #fff;
}
html.dark .nav-tab.active {
    color: var(--bg);
}

/* --- Signature element: due-date "stamp" countdown badge -------------- */
.stamp {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.75rem;
    border: 1.5px dashed var(--accent);
    border-radius: 0.5rem;
    background-color: color-mix(in srgb, var(--accent) 10%, transparent);
    color: var(--accent);
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.8rem;
    letter-spacing: 0.02em;
}
.stamp.stamp-danger {
    border-color: var(--danger);
    color: var(--danger);
    background-color: color-mix(in srgb, var(--danger) 10%, transparent);
}
.stamp.stamp-muted {
    border-color: var(--ink-muted);
    color: var(--ink-muted);
    background-color: transparent;
}

/* --- Cards -------------------------------------------------------------*/
.card {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.9rem;
}

/* --- Course color chip --------------------------------------------------*/
.course-chip {
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 9999px;
    display: inline-block;
    flex-shrink: 0;
}

/* --- Modal ---------------------------------------------------------------*/
.modal-backdrop {
    position: fixed;
    inset: 0;
    z-index: 50;
    background-color: rgba(20, 22, 27, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}
.modal-panel {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1rem;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

/* --- Form fields -----------------------------------------------------*/
.field-label {
    font-size: 0.8125rem;
    font-weight: 500;
    margin-bottom: 0.3rem;
    display: block;
}
.field-input {
    width: 100%;
    padding: 0.55rem 0.75rem;
    font-size: 0.875rem;
    border-radius: 0.55rem;
    background-color: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--ink);
}
.field-input:focus {
    outline: none;
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 25%, transparent);
}
.field-error {
    font-size: 0.75rem;
    color: var(--danger);
    margin-top: 0.25rem;
}

/* --- Scrollbar (subtle) --------------------------------------------------*/
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background-color: var(--border); border-radius: 999px; }
::-webkit-scrollbar-track { background: transparent; }