/* ==================== Design System ==================== */
:root {
    --bg-dark: #05070a;
    --card-bg: rgba(15, 23, 42, 0.7);
    --sidebar-bg: #0a0f1e;
    --accent: #00d2ff;
    --accent-glow: rgba(0, 210, 255, 0.4);
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    --danger: #ef4444;
    --success: #22c55e;
    --glass: rgba(255, 255, 255, 0.03);
    --border: rgba(255, 255, 255, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Cairo', sans-serif;
}

body {
    background: var(--bg-dark);
    color: var(--text-main);
    height: 100vh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hidden {
    display: none !important;
}

/* ==================== Calculator Styling ==================== */
.calculator-wrapper {
    perspective: 1000px;
    z-index: 10;
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.calculator {
    background: var(--card-bg);
    width: 360px;
    padding: 25px;
    border-radius: 35px;
    border: 1px solid var(--border);
    box-shadow: 0 40px 100px rgba(0, 0, 0, 0.8), inset 0 1px 1px rgba(255, 255, 255, 0.1);
}

.calc-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
    color: var(--text-dim);
    font-size: 0.85rem;
    font-weight: 600;
}

.display {
    background: #020617;
    height: 120px;
    border-radius: 20px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: flex-end;
    margin-bottom: 25px;
    border: 1px solid var(--border);
    box-shadow: inset 0 4px 12px rgba(0, 0, 0, 0.5);
}

.previous-operand {
    font-size: 1.1rem;
    color: var(--text-dim);
    min-height: 1.5rem;
}

.current-operand {
    font-size: 2.8rem;
    font-family: 'Orbitron', sans-serif;
    color: var(--text-main);
    letter-spacing: 2px;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.btn {
    height: 65px;
    border: none;
    border-radius: 18px;
    font-size: 1.3rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    background: #1e293b;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn:hover {
    transform: translateY(-3px);
    background: #334155;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.btn:active {
    transform: translateY(0);
}

.operator-btn {
    color: #ff9f0a;
    background: rgba(255, 159, 10, 0.1);
}

.action-btn {
    color: #ff453a;
    background: rgba(255, 69, 58, 0.1);
}

.equals-btn {
    background: var(--accent);
    color: #000;
}

.col-2 {
    grid-column: span 2;
}

/* ==================== Vault Overlay ==================== */
.vault-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-dark);
    display: flex;
    z-index: 100;
    animation: slideIn 0.6s cubic-bezier(0.19, 1, 0.22, 1);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: scale(1.1);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

.sidebar {
    width: 280px;
    background: var(--sidebar-bg);
    border-left: 1px solid var(--border);
    padding: 40px 25px;
    display: flex;
    flex-direction: column;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 15px;
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 50px;
}

.brand-icon {
    width: 45px;
    height: 45px;
    background: var(--accent-glow);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 10px;
    flex-grow: 1;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-dim);
    padding: 15px 20px;
    border-radius: 15px;
    text-align: right;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: 0.3s;
}

.nav-btn i {
    width: 20px;
    font-size: 1.1rem;
}

.nav-btn:hover,
.nav-btn.active {
    background: var(--glass);
    color: var(--accent);
}

.exit-btn {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
    padding: 15px;
    border-radius: 15px;
    width: 100%;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

/* Main Content Area */
.vault-main {
    flex-grow: 1;
    padding: 50px;
    overflow-y: auto;
}

.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
}

.header-info h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
}

.header-info p {
    color: var(--text-dim);
}

.add-btn {
    background: var(--accent);
    color: #000;
    border: none;
    padding: 12px 25px;
    border-radius: 50px;
    font-weight: 700;
    cursor: pointer;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    margin-bottom: 50px;
}

.stat-item {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 25px;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 25px;
}

.stat-icon {
    width: 65px;
    height: 65px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.img-bg {
    background: rgba(59, 130, 246, 0.15);
    color: #3b82f6;
}

.vid-bg {
    background: rgba(168, 85, 247, 0.15);
    color: #a855f7;
}

.doc-bg {
    background: rgba(34, 197, 94, 0.15);
    color: #22c55e;
}

.count {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
}

.label {
    color: var(--text-dim);
    font-size: 0.9rem;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 100px 0;
    color: var(--text-dim);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.2;
}

/* Notifications */
.notif {
    position: fixed;
    top: 30px;
    background: var(--accent);
    color: #000;
    padding: 15px 40px;
    border-radius: 50px;
    font-weight: 700;
    box-shadow: 0 10px 30px var(--accent-glow);
    z-index: 2000;
    animation: fadeInDown 0.4s ease;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== Mobile Navigation ==================== */
.mobile-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--sidebar-bg);
    padding: 12px 20px;
    padding-bottom: max(12px, env(safe-area-inset-bottom));
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.4);
    z-index: 1000;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--border);
}

.mobile-nav-items {
    display: flex;
    justify-content: space-around;
    align-items: center;
}

.mobile-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 8px 20px;
    color: var(--text-dim);
    background: none;
    border: none;
    font-size: 11px;
    border-radius: 12px;
    transition: all 0.3s ease;
    cursor: pointer;
    font-family: inherit;
}

.mobile-nav-item i {
    font-size: 22px;
    transition: all 0.3s ease;
}

.mobile-nav-item.active,
.mobile-nav-item:hover {
    color: var(--accent);
    background: rgba(0, 210, 255, 0.1);
}

.mobile-nav-item.active i {
    transform: translateY(-3px);
    filter: drop-shadow(0 4px 8px var(--accent-glow));
}

/* Floating Action Button */
.fab {
    display: none;
    position: fixed;
    bottom: 100px;
    left: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), #00a8cc);
    color: #000;
    border: none;
    font-size: 26px;
    cursor: pointer;
    z-index: 999;
    box-shadow: 0 6px 25px rgba(0, 210, 255, 0.5);
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.fab:active {
    transform: scale(0.9);
}

/* Touch-friendly buttons */
@media (hover: none) and (pointer: coarse) {

    .btn,
    .nav-btn,
    .add-btn,
    .exit-btn {
        min-height: 48px;
        min-width: 48px;
    }

    .buttons {
        gap: 12px;
    }

    .btn {
        font-size: 1.4rem;
    }
}

/* Mobile Layout */
@media (max-width: 768px) {
    .mobile-nav {
        display: block;
    }

    .fab {
        display: flex;
    }

    .calculator-wrapper {
        padding: 20px;
        padding-bottom: 100px;
    }

    .calculator {
        width: 100%;
        max-width: 400px;
    }

    .vault-overlay {
        flex-direction: column;
    }

    .sidebar {
        display: none;
    }

    .vault-main {
        padding: 20px;
        padding-bottom: 120px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .header-actions {
        display: none;
    }

    .main-header {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
}

/* ==================== Note Manager Styling ==================== */
.note-manager {
    background: var(--glass);
    backdrop-filter: blur(var(--backdrop-blur));
    border: 1px solid var(--border);
    border-radius: 25px;
    padding: 30px;
    margin-top: 30px;
}

.note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.note-input-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

#vault-note-area {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border);
    border-radius: 15px;
    padding: 20px;
    color: var(--text-main);
    font-size: 1.1rem;
    min-height: 200px;
    resize: vertical;
    outline: none;
    transition: 0.3s;
}

#vault-note-area:focus {
    border-color: var(--accent);
    box-shadow: 0 0 15px var(--accent-glow);
}

.save-note-btn {
    align-self: flex-end;
    background: var(--accent);
    color: #000;
    border: none;
    padding: 10px 30px;
    border-radius: 50px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: 0.3s;
}

.save-note-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px var(--accent-glow);
}

/* Glass Enhancement for Calculator */
.calculator {
    backdrop-filter: blur(var(--backdrop-blur));
}

.btn {
    background: rgba(30, 41, 59, 0.4);
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.btn:hover {
    background: rgba(51, 65, 85, 0.6);
}