:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    /* 배경 그라데이션은 유지하되 조금 더 부드럽게 */
    --bg-gradient: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
    /* 밝은 테마용 변수 */
    --glass-bg: rgba(255, 255, 255, 0.9);
    --glass-border: rgba(255, 255, 255, 0.6);
    --text-primary: #1f2937;
    /* 진한 회색 */
    --text-secondary: #6b7280;
    /* 연한 회색 */
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

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

body {
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--text-primary);
}

#root {
    width: 100%;
    max-width: 500px;
    padding: 20px;
}

.app-container {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
    animation: fadeIn 0.8s ease-out;
}

h1 {
    font-size: 2.2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
    color: #111827;
    letter-spacing: -0.5px;
    text-shadow: none;
}

.input-group {
    display: flex;
    gap: 12px;
    margin-bottom: 2rem;
    position: relative;
}

.todo-input {
    flex: 1;
    background: #ffffff;
    border: 2px solid #e5e7eb;
    padding: 1rem 1.2rem;
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s ease;
    outline: none;
}

.todo-input::placeholder {
    color: #9ca3af;
}

.todo-input:focus {
    background: #ffffff;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.add-btn {
    background: var(--primary);
    border: none;
    color: white;
    width: 56px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.2rem;
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.3);
}

.add-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px -3px rgba(99, 102, 241, 0.4);
}

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

.todo-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.todo-item {
    background: #ffffff;
    padding: 1rem;
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s ease;
    border: 1px solid #f3f4f6;
    animation: slideIn 0.3s ease-out forwards;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

.todo-item:hover {
    background: #f9fafb;
    transform: translateY(-2px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    border-color: #e5e7eb;
}

.todo-text {
    font-size: 1.05rem;
    word-break: break-all;
    margin-right: 1rem;
    color: #374151;
    font-weight: 500;
}

.delete-btn {
    background: #f3f4f6;
    border: none;
    color: #9ca3af;
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s ease;
    min-width: 36px;
    min-height: 36px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.delete-btn:hover {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 2rem 0;
    font-style: italic;
    opacity: 0.7;
}

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

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

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

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

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}