:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --success-color: #27ae60;
    --info-color: #17a2b8;
    --light-bg: #f8f9fa;
    --border-radius: 12px;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin-bottom: 3rem;
}

.header-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, #34495e 100%);
    color: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--box-shadow);
    border: none;
}

.header-card h1 {
    font-weight: 700;
    margin-bottom: 0.5rem;
    font-size: 2.2rem;
}

.header-card .subtitle {
    opacity: 0.9;
    font-size: 1.1rem;
}

.warning-alert {
    background: #fff3cd;
    border: 2px solid var(--warning-color);
    border-radius: var(--border-radius);
    padding: 1rem 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--box-shadow);
    display: flex;
    align-items: center;
}

.warning-alert .alert-icon {
    color: var(--danger-color);
    font-size: 1.5rem;
    margin-right: 15px;
    flex-shrink: 0;
}

.calculator-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 2.5rem;
    box-shadow: var(--box-shadow);
    margin-bottom: 2rem;
    border: none;
}

.form-group {
    margin-bottom: 2rem;
}

.section-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.section-title i {
    color: var(--secondary-color);
}

.form-label {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-label i {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

.form-control,
.form-select {
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    transition: var(--transition);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 0.25rem rgba(52, 152, 219, 0.25);
}

.form-text {
    font-size: 0.85rem;
    margin-top: 0.4rem;
    color: #6c757d;
    font-style: italic;
}

.input-group-icon {
    position: relative;
}

.input-group-icon .form-control {
    padding-left: 2.5rem;
}

.input-group-icon i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: #6c757d;
    z-index: 10;
}

.optional-field {
    opacity: 0.7;
    transition: var(--transition);
}

.optional-field.active {
    opacity: 1;
}

.optional-field.disabled {
    opacity: 0.4;
    pointer-events: none;
}

.optional-field.disabled .form-control,
.optional-field.disabled .form-select {
    background-color: #f8f9fa;
    border-color: #e9ecef;
}

.btn-calculate {
    background: linear-gradient(135deg, var(--success-color) 0%, #2ecc71 100%);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(39, 174, 96, 0.3);
}

.btn-calculate:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(39, 174, 96, 0.4);
}

.btn-calendar {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
}

.btn-calendar:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.4);
}

.button-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.results-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 2.5rem;
    box-shadow: var(--box-shadow);
    margin-top: 2rem;
    display: none;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.results-header {
    background: linear-gradient(135deg, var(--info-color) 0%, #138496 100%);
    color: white;
    padding: 1.5rem;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    margin: -2.5rem -2.5rem 2rem -2.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.results-header h3 {
    margin: 0;
    font-weight: 600;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.1rem;
}

.days-counter {
    text-align: center;
    padding: 2rem;
    margin: 1.5rem 0;
    border-radius: var(--border-radius);
    background: linear-gradient(135deg, var(--light-bg) 0%, #e9ecef 100%);
}

.days-number {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
    margin-bottom: 0.5rem;
}

.days-label {
    font-size: 1.2rem;
    color: #6c757d;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.date-card {
    background: white;
    border: 2px solid var(--secondary-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 1rem 0;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.date-card .icon {
    background: var(--secondary-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.date-card .content {
    flex: 1;
}

.date-card .label {
    font-size: 0.9rem;
    color: #6c757d;
    margin-bottom: 0.25rem;
}

.date-card .value {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
}

.warning-box {
    background: #ffeaa7;
    border: 2px solid var(--warning-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-top: 2rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.warning-box i {
    color: var(--danger-color);
    font-size: 1.5rem;
    flex-shrink: 0;
    margin-top: 0.2rem;
}

.info-box {
    background: #e8f4fc;
    border-left: 4px solid var(--secondary-color);
    padding: 1.5rem;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    margin-top: 2rem;
}

.info-box h5 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.passport-flag {
    display: inline-block;
    width: 24px;
    height: 16px;
    margin-right: 8px;
    border: 1px solid #ddd;
    vertical-align: middle;
    background-size: cover;
}

.passport-flag.cn {
    background: linear-gradient(to right, #de2910 33%, #ffde00 33%, #ffde00 66%, #de2910 66%);
}

.passport-flag.hk {
    background-color: #de2910;
}

.passport-flag.mo {
    background-color: #009543;
}

.passport-flag.tw {
    background: linear-gradient(to right, #fe0000 33%, #000095 33%, #000095 66%, #fe0000 66%);
}

.passport-flag.jp {
    background-color: white;
}

.passport-flag.kr {
    background-color: white;
}

.passport-flag.sg {
    background: linear-gradient(to bottom, #ed2939 50%, white 50%);
}

.passport-flag.ml {
    background: linear-gradient(to bottom, #cc0001 33%, white 33%, white 66%, #010066 66%);
}

.passport-flag.ca {
    background-color: #ff0000;
}

.passport-flag.kz {
    background-color: #00afca;
}

.passport-flag.ru {
    background: linear-gradient(to bottom, #fff 33%, #0039a6 33%, #0039a6 66%, #d52b1e 66%);
}

.status-safe {
    color: var(--success-color);
}

.status-warning {
    color: var(--warning-color);
}

.status-danger {
    color: var(--danger-color);
}

.days-remaining {
    font-size: 1.3rem;
    font-weight: 600;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    display: inline-block;
    margin: 0.5rem 0;
}

.days-remaining.safe {
    background: rgba(39, 174, 96, 0.1);
    color: var(--success-color);
}

.days-remaining.warning {
    background: rgba(243, 156, 18, 0.1);
    color: var(--warning-color);
}

.days-remaining.danger {
    background: rgba(231, 76, 60, 0.1);
    color: var(--danger-color);
}

/* 响应式设计优化 */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .calculator-card,
    .results-card {
        padding: 1.5rem;
    }

    .header-card h1 {
        font-size: 1.8rem;
    }

    .days-number {
        font-size: 3rem;
    }

    .button-group {
        flex-direction: column;
        gap: 0.75rem;
    }

    .btn-calculate,
    .btn-calendar {
        width: 100%;
        justify-content: center;
        padding: 0.875rem 1.5rem;
    }

    .results-header {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
        padding: 1rem;
    }

    .date-card {
        padding: 1rem;
    }

    .date-card .icon {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }

    .date-card .value {
        font-size: 1.1rem;
    }
}

@media (max-width: 576px) {
    .header-card {
        padding: 1.5rem;
    }

    .calculator-card,
    .results-card {
        padding: 1.25rem;
    }

    .section-title {
        font-size: 1.2rem;
    }

    .days-number {
        font-size: 2.5rem;
    }

    .form-group {
        margin-bottom: 1.5rem;
    }
}

/* 加载状态 */
.loading {
    display: none;
    text-align: center;
    padding: 2rem;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--secondary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

.optional-tag {
    display: inline-block;
    background: #6c757d;
    color: white;
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: 8px;
    vertical-align: middle;
}

/* 超期状态 */
.days-counter.text-danger .days-number {
    color: #dc3545 !important;
    font-size: 3.5rem;
}

.border-danger {
    border-color: #dc3545 !important;
}

.bg-danger.bg-opacity-10 {
    background-color: rgba(220, 53, 69, 0.1) !important;
}

/* 按钮优化 */
.btn-warning {
    background: linear-gradient(135deg, #ffc107 0%, #ff9800 100%);
    color: #212529;
    border: none;
    box-shadow: 0 4px 15px rgba(255, 193, 7, 0.3);
}

.btn-warning:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 193, 7, 0.4);
}

.btn-outline-primary {
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    background: transparent;
}

.btn-outline-primary:hover {
    background: var(--secondary-color);
    color: white;
}

/* 动画优化 */
@keyframes headShake {

    0%,
    50% {
        transform: translateX(0);
    }

    6.5%,
    31.5% {
        transform: translateX(-6px) rotateY(-9deg);
    }

    18.5%,
    43.5% {
        transform: translateX(5px) rotateY(7deg);
    }
}

/* Modal样式优化 */
.custom-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1050;
    display: none;
}

.custom-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(3px);
}

.custom-modal-content {
    position: relative;
    background: white;
    margin: 50px auto;
    max-width: 800px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    animation: modalSlideIn 0.3s ease;
    max-height: 90vh;
    overflow: hidden;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }

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

.custom-modal-header {
    padding: 1.5rem;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 10;
}

.custom-modal-header h5 {
    margin: 0;
    font-weight: 600;
    font-size: 1.25rem;
}

.custom-modal-close {
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.custom-modal-close:hover {
    opacity: 1;
}

.custom-modal-body {
    padding: 1.5rem;
    max-height: calc(90vh - 120px);
    overflow-y: auto;
}

.custom-modal-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid #dee2e6;
    text-align: right;
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

/* 表单验证样式 */
.is-invalid {
    border-color: var(--danger-color) !important;
}

.invalid-feedback {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none;
}

.is-invalid~.invalid-feedback {
    display: block;
}

/* 打印优化 */
@media print {
    .no-print {
        display: none !important;
    }

    body {
        background: white !important;
    }

    .container {
        margin: 0;
        padding: 0;
        max-width: 100%;
    }

    .calculator-card,
    .results-card {
        box-shadow: none !important;
        border: 1px solid #dee2e6 !important;
        page-break-inside: avoid;
    }

    .btn {
        display: none !important;
    }
}