:root {
    --primary-color: #4DA89D;
    --primary-dark: #3d8a80;
    --secondary-color: #4DA89D;
    --success-color: #4cc9f0;
    --error-color: #f72585;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #2b2d42;
    --text-light: #8d99ae;
    --border-color: #e9ecef;
    --shadow: 0 10px 20px rgba(0, 0, 0, 0.08);
    --primary-rgb: 77, 168, 157;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', 'Noto Sans SC', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    background-color: var(--bg-color);
    color: var(--text-color);
    padding: 20px;
    min-height: 100vh;
    transition: var(--transition);
    background-image: radial-gradient(circle at 10% 20%, rgba(var(--primary-rgb), 0.05) 0%, rgba(var(--primary-rgb), 0.05) 90%);
}

.container {
    max-width: 680px;
    margin: 2rem auto;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    position: relative;
}

.header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem 2rem 2.5rem;
    text-align: center;
    position: relative;
    transition: var(--transition);
}

.header::after {
    content: "";
    position: absolute;
    bottom: -20px;
    left: 0;
    right: 0;
    height: 40px;
    background: var(--card-bg);
    border-radius: 20px 20px 0 0;
    z-index: 1;
    transition: var(--transition);
}

.header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    position: relative;
    z-index: 2;
}

.header p {
    font-size: 0.95rem;
    opacity: 0.9;
    position: relative;
    z-index: 2;
}

.content {
    padding: 2rem;
    position: relative;
    z-index: 2;
}

.form-group {
    margin-bottom: 1.8rem;
}

label {
    display: block;
    margin-bottom: 0.6rem;
    font-weight: 500;
    color: var(--text-color);
    font-size: 0.95rem;
}

.input-wrapper {
    position: relative;
}

input[type="text"],
input[type="date"],
textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
    background-color: #fcfcfc;
}

input[type="date"] {
    appearance: none;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%238d99ae'%3E%3Cpath d='M19 3h-1V1h-2v2H8V1H6v2H5c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h14c1.1 0 2-.9 2-2V5c0-1.1-.9-2-2-2zm0 16H5V9h14v10z'/%3E%3C/svg%3E") no-repeat 95% center/20px;
}

input:focus,
textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.2);
    outline: none;
    background-color: white;
}

.button-group {
    display: flex;
    gap: 12px;
    margin-top: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 1rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.btn.primary {
    background: var(--primary-color);
    color: white;
    flex: 1;
}

.btn.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(var(--primary-rgb), 0.3);
}

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

.btn.secondary {
    background: #f1f3f5;
    color: var(--text-color);
}

.btn.secondary:hover {
    background: #e9ecef;
}

.result-container {
    margin-top: 2rem;
}

.result-container h2 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.result-box {
    position: relative;
    border-radius: var(--radius-sm);
    background: #f8f9fa;
    border: 2px dashed var(--border-color);
    padding: 1.2rem;
}

#result {
    font-family: 'Courier New', monospace;
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--primary-color);
    text-align: center;
    letter-spacing: 2px;
    /* padding-right: 150px; */
    background: transparent;
    border: none;
    resize: none;
    width: calc(100% - 150px);
}

#monthly-results {
    margin-top: 1rem;
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 10px;
    display: none;
}

.monthly-result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px;
    border-bottom: 1px solid var(--border-color);
}

.monthly-result-item:last-child {
    border-bottom: none;
}

.monthly-result-date {
    font-weight: 500;
    min-width: 120px;
}

.monthly-result-code {
    font-family: 'Courier New', monospace;
    font-weight: bold;
    color: var(--primary-color);
    margin: 0 10px;
    flex-grow: 1;
    text-align: center;
}

.copy-btn {
    position: absolute;
    right: 15px;
    top: 25%;
    transform: translateY(-50%);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.6rem 1.2rem;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 5px;
    background: var(--primary-color);
}

.copy-btn-adb {
    /* right: 70px; */
    top: 75%;
}

.copy-btn:hover {
    background: var(--primary-dark);
}

.copy-btn:active {
    transform: translateY(-50%) scale(0.96);
}

.error-message {
    color: var(--error-color);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    display: none;
}

.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 15px 25px;
    border-radius: var(--radius-sm);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    display: flex;
    align-items: center;
    transform: translateX(150%);
    transition: var(--transition);
}

.toast.show {
    transform: translateX(0);
}

.toast-icon {
    margin-right: 10px;
    font-size: 1.2rem;
}

.theme-controls {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 10;
}

.theme-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid white;
    cursor: pointer;
    transition: var(--transition);
    background: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.theme-btn:hover {
    transform: scale(1.1);
}

.theme-picker {
    display: none;
    position: absolute;
    top: 50px;
    right: 0;
    background: var(--card-bg);
    padding: 15px;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    z-index: 11;
    width: 230px;
}

.theme-picker.show {
    display: block;
    animation: fadeIn 0.3s;
}

.theme-options {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-bottom: 15px;
}

.theme-option {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
}

.theme-option:hover {
    transform: scale(1.1);
}

.theme-option.active {
    border-color: var(--text-color);
}

.custom-color-picker {
    margin-top: 15px;
}

.custom-color-picker input {
    width: 100%;
    height: 40px;
    cursor: pointer;
    border: none;
    background: transparent;
}

.theme-actions {
    display: flex;
    justify-content: space-between;
    margin-top: 15px;
    gap: 10px;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }

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

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .container {
        margin: 1rem auto;
    }

    .header {
        padding: 1.5rem 1.5rem 2.5rem;
    }

    .content {
        padding: 1.5rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .button-group {
        flex-direction: column;
    }

    .monthly-result-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }

    .monthly-result-code {
        text-align: left;
        margin: 5px 0;
        width: 100%;
    }

    .toast {
        top: 10px;
        right: 10px;
        left: 10px;
        transform: translateY(-150%);
    }

    .toast.show {
        transform: translateY(0);
    }
}

@media (min-width: 992px) {
    .form-group {
        display: grid;
        grid-template-columns: 140px 1fr;
        gap: 1.5rem;
        align-items: center;
    }

    label {
        margin-bottom: 0;
        text-align: right;
    }
}