/* Reset và font */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #1f2937;
}

/* App container */
.app {
    display: flex;
    min-height: 100vh;
    backdrop-filter: blur(2px);
}

/* Sidebar - responsive */
.sidebar {
    width: 280px;
    background: rgba(17, 24, 39, 0.9);
    backdrop-filter: blur(10px);
    color: white;
    padding: 2rem 1.5rem;
    box-shadow: 2px 0 20px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.sidebar h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    font-weight: 600;
    background: linear-gradient(135deg, #fff, #a78bfa);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.sidebar a {
    display: inline-block;
    margin-top: 2rem;
    color: #e2e8f0;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    padding: 0.5rem 1rem;
    border-radius: 12px;
    background: rgba(255,255,255,0.1);
}

.sidebar a:hover {
    background: rgba(255,255,255,0.2);
    transform: translateX(5px);
}

/* Main content */
.main {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

/* Card style với hiệu ứng lung linh */
.card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-radius: 28px;
    padding: 1.8rem;
    margin-bottom: 2rem;
    box-shadow: 0 20px 35px -10px rgba(0,0,0,0.2), 0 0 0 1px rgba(255,255,255,0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 40px -12px rgba(0,0,0,0.25), 0 0 0 1px rgba(255,255,255,0.3);
}

.card h3 {
    font-size: 1.6rem;
    margin-bottom: 1.2rem;
    font-weight: 600;
    background: linear-gradient(135deg, #4f46e5, #3b82f6);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* Form elements */
input, select, textarea {
    width: 100%;
    padding: 14px 16px;
    margin-top: 12px;
    border-radius: 20px;
    border: 1px solid #e2e8f0;
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.2s;
    background: white;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: #8b5cf6;
    box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.2);
}

button {
    width: 100%;
    padding: 14px;
    margin-top: 20px;
    background: linear-gradient(135deg, #4f46e5, #3b82f6);
    color: white;
    border: none;
    border-radius: 40px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

button:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.4);
}

/* Reminder items */
.item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid #eef2ff;
    transition: all 0.2s;
}

.item:hover {
    background: rgba(139, 92, 246, 0.05);
    padding-left: 10px;
    border-radius: 20px;
}

.item b {
    font-size: 1.1rem;
    white-space: pre-wrap;
    word-break: break-word;
}

.time {
    font-size: 0.8rem;
    color: #6b7280;
    margin-top: 4px;
}

.badge {
    background: #10b981;
    color: white;
    padding: 4px 8px;
    border-radius: 30px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-left: 8px;
}

.badge.done {
    background: #10b981;
}

.item a {
    color: #ef4444;
    text-decoration: none;
    font-size: 1.2rem;
    margin-left: 12px;
    transition: transform 0.2s;
    display: inline-block;
}

.item a:hover {
    transform: scale(1.1);
}

/* Toast */
#toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: #1f2937;
    color: white;
    padding: 12px 24px;
    border-radius: 40px;
    font-size: 0.9rem;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    display: none;
    z-index: 1000;
    backdrop-filter: blur(8px);
    background: rgba(31, 41, 55, 0.9);
}

/* Animation */
.fade-in {
    animation: fadeInUp 0.6s cubic-bezier(0.2, 0.9, 0.4, 1.1);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive cho điện thoại */
@media (max-width: 768px) {
    .app {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        padding: 1rem 1.5rem;
        text-align: center;
    }

    .sidebar h2 {
        font-size: 1.5rem;
        margin-bottom: 1rem;
    }

    .sidebar a {
        margin-top: 0.5rem;
    }

    .main {
        padding: 1.2rem;
    }

    .card {
        padding: 1.2rem;
        border-radius: 24px;
    }

    .card h3 {
        font-size: 1.3rem;
    }

    input, select, textarea {
        padding: 12px;
        font-size: 0.95rem;
    }

    button {
        padding: 12px;
    }

    .item b {
        font-size: 1rem;
    }
}