/* --- NEO-BRUTALIST DESIGN TOKENS --- */
:root {
    --font-family: 'IBM Plex Mono', monospace;
    --bg: #f5f5f5;
    --text: #171717;
    /* Borders & Shadows - Mobile First */
    --border-width: 2px;
    --border-color: #171717;
    --shadow-x: 4px;
    --shadow-y: 4px;
    --shadow-color: #171717;
    /* Core Palette */
    --white: #ffffff;
    --yellow: #fef08a;
    --blue: #bfdbfe;
    --green: #bbf7d0;
    --red: #fecaca;
    /* Status Palette */
    --past-bg: #e7e5e4;
    --past-text: #78716c;
    --past-border: #a8a29e;
    --current-class-bg: var(--yellow);
    --next-class-bg: var(--blue);
    --progress-bar-fill: #1cdd63;
    /* Attendance Palette */
    --present-bg: var(--green);
    --absent-bg: var(--red);
    --selected-day-bg: var(--blue);
}

/* --- DESKTOP-ONLY OVERRIDES --- */
@media (min-width: 768px) {
    :root {
        --border-width: 3px;
        --shadow-x: 6px;
        --shadow-y: 6px;
    }
}


html,
body {
    font-family: var(--font-family);
}

body {
    background-color: var(--bg);
    color: var(--text);
    /* Prevents double-tap to zoom on mobile */
    touch-action: manipulation;
}

/* --- CORE COMPONENTS (MOBILE FIRST) --- */
.card {
    background-color: var(--white);
    border: var(--border-width) solid var(--border-color);
    box-shadow: var(--shadow-x) var(--shadow-y) 0 0 var(--shadow-color);
    position: relative;
    overflow: hidden;
    /* Mobile-first: No hover transform */
    transition: background-color 0.15s ease-out;
}

.btn {
    font-weight: 700;
    border: var(--border-width) solid var(--border-color);
    box-shadow: calc(var(--shadow-x) * 0.7) calc(var(--shadow-y) * 0.7) 0 0 var(--shadow-color);
    background-color: var(--white);
    transition: background-color 0.1s ease-out, color 0.1s ease-out, transform 0.1s ease-out, box-shadow 0.1s ease-out;
    text-transform: uppercase;
}

.btn:active:not(:disabled),
.btn-active {
    background-color: var(--yellow);
    /* No transform on mobile for a flatter feel */
}

/* --- DESKTOP-ONLY INTERACTIVE STYLES --- */
@media (min-width: 768px) {
    .card:hover {
        transform: translate(calc(var(--shadow-x) * -0.25), calc(var(--shadow-y) * -0.25));
        box-shadow: calc(var(--shadow-x) * 1.25) calc(var(--shadow-y) * 1.25) 0 0 var(--shadow-color);
    }

    .btn:hover:not(:disabled) {
        transform: translate(-2px, -2px);
        box-shadow: calc(var(--shadow-x) * 0.8) calc(var(--shadow-y) * 0.8) 0 0 var(--shadow-color);
    }

    .btn:active:not(:disabled),
    .btn-active {
        /* Desktop-only "press down" effect */
        transform: translate(calc(var(--shadow-x) * 0.7), calc(var(--shadow-y) * 0.7));
        box-shadow: none;
        background-color: var(--yellow);
    }
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.main-nav-tab {
    border: var(--border-width) solid var(--border-color);
    border-bottom: var(--border-width) solid var(--border-color);
    background-color: var(--past-bg);
    color: var(--past-text);
    padding: 0.6rem 0.75rem;
    /* Smaller padding for mobile */
    font-size: 0.875rem;
    /* Smaller font for mobile */
    font-weight: 700;
    text-transform: uppercase;
    position: relative;
    top: var(--border-width);
    transition: all 0.15s ease-out;
}

/* Increase tab padding on larger screens */
@media (min-width: 640px) {
    .main-nav-tab {
        padding: 0.75rem 1.5rem;
    }
}

.main-nav-tab.tab-active {
    background-color: var(--white);
    color: var(--text);
    border-bottom-color: transparent;
}

/* --- UI SPECIFIC STYLES --- */
.past-element {
    background-color: var(--past-bg) !important;
    color: var(--past-text) !important;
    border-color: var(--past-border);
    box-shadow: var(--shadow-x) var(--shadow-y) 0 0 var(--past-border);
}

.current-class {
    background-color: var(--current-class-bg) !important;
}

.next-class {
    background-color: var(--next-class-bg) !important;
}

.progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 6px;
    background-color: var(--progress-bar-fill);
    width: 0%;
    transition: width 1s linear;
}

.subject-color-tag {
    border-left-width: 6px;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.125rem;
    /* Tighter gap for mobile */
}

@media (min-width: 768px) {
    .calendar-grid {
        gap: 0.5rem;
    }
}

.calendar-day {
    border: var(--border-width) solid transparent;
    font-weight: 700;
    transition: all 0.15s ease-out;
    padding: 0.5rem 0.125rem;
    /* Smaller padding for smaller tiles */
}

.calendar-day.selected {
    background-color: var(--selected-day-bg);
    border-color: var(--border-color);
}

.calendar-day.present {
    background-color: var(--present-bg);
}

.calendar-day.absent {
    background-color: var(--absent-bg);
}

.calendar-day:not(.disabled):hover {
    background-color: var(--yellow);
}

.calendar-day.disabled-day {
    background-color: #e7e5e4;
    color: #a8a29e;
    cursor: not-allowed;
}

#toast {
    position: fixed;
    bottom: 1.5rem;
    left: 50%;
    z-index: 50;
    transform: translateX(-50%);
    transition: opacity 0.3s ease, transform 0.3s ease;
    opacity: 0;
    pointer-events: none;
}

#toast.show {
    opacity: 1;
    transform: translate(-50%, -10px);
}

.mobile-day-selector {
    position: sticky;
    top: -1px;
    background-color: var(--bg);
    z-index: 10;
    padding: 0.5rem;
    border-bottom: var(--border-width) solid var(--border-color);
}