:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    background: #f1f5f9;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    min-height: 100vh;
    padding-bottom: 40px;
}
.install-header {
    background: var(--gradient);
    color: #fff;
    text-align: center;
    padding: 48px 20px 40px;
    position: relative;
    overflow: hidden;
}
.install-header::before {
    content: "";
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
    animation: headerPulse 8s ease-in-out infinite;
}
@keyframes headerPulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 1; }
}
.install-header h1 {
    font-size: 30px;
    font-weight: 700;
    letter-spacing: 1px;
    position: relative;
    z-index: 1;
}
.install-header p {
    opacity: 0.9;
    font-size: 15px;
    margin-top: 8px;
    position: relative;
    z-index: 1;
}
.install-container {
    max-width: 740px;
    margin: -24px auto 0;
    padding: 0 16px;
    position: relative;
    z-index: 2;
}
.install-card {
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.06), 0 1px 4px rgba(0,0,0,0.04);
    overflow: hidden;
}

/* Stepper */
.stepper {
    display: flex;
    padding: 28px 24px 20px;
    background: linear-gradient(to bottom, #fafbff, #fff);
    border-bottom: 1px solid #f0f0f5;
}
.stepper-item {
    flex: 1;
    text-align: center;
    position: relative;
}
.stepper-item::before {
    content: "";
    position: absolute;
    top: 18px;
    left: 0;
    right: 50%;
    height: 3px;
    background: #e2e8f0;
    border-radius: 2px;
    transition: background 0.4s;
}
.stepper-item::after {
    content: "";
    position: absolute;
    top: 18px;
    left: 50%;
    right: 0;
    height: 3px;
    background: #e2e8f0;
    border-radius: 2px;
    transition: background 0.4s;
}
.stepper-item:first-child::before { display: none; }
.stepper-item:last-child::after { display: none; }
.stepper-item.active::before,
.stepper-item.completed::before,
.stepper-item.completed::after {
    background: var(--primary);
}
.stepper-number {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: #e2e8f0;
    color: #94a3b8;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    font-weight: 700;
    position: relative;
    z-index: 1;
    transition: all 0.4s;
    line-height: 1;
}
.stepper-item.active .stepper-number {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 12px rgba(99,102,241,0.4);
}
.stepper-item.completed .stepper-number {
    background: var(--success);
    color: #fff;
    box-shadow: 0 2px 8px rgba(16,185,129,0.3);
}
.stepper-label {
    display: block;
    font-size: 13px;
    color: #94a3b8;
    margin-top: 8px;
    font-weight: 500;
    transition: color 0.3s;
}
.stepper-item.active .stepper-label { color: var(--primary); }
.stepper-item.completed .stepper-label { color: var(--success); }

/* Step content */
.step-content { padding: 32px 30px; }
.step-panel { display: none; }
.step-panel.active { display: block; animation: fadeInUp 0.4s ease; }
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}
.section-title {
    font-size: 16px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.section-title i {
    color: var(--primary);
    font-size: 18px;
}
.section-title::after {
    content: "";
    flex: 1;
    height: 2px;
    background: linear-gradient(to right, var(--primary-light), transparent);
    margin-left: 12px;
}

/* Env check table */
.env-table { border-radius: 10px; overflow: hidden; border: 1px solid #e2e8f0; }
.env-table th {
    background: #f8fafc;
    font-weight: 600;
    font-size: 13px;
    color: #475569;
    padding: 8px 16px;
    border-bottom: 2px solid #e2e8f0;
}
.env-table td {
    padding: 7px 16px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #f1f5f9;
    vertical-align: middle;
}
.env-table tr:last-child td { border-bottom: none; }
.check-pass { color: var(--success); font-weight: 600; }
.check-fail { color: var(--danger); font-weight: 600; }

/* Form */
.form-section {
    background: #fafbff;
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
    border: 1px solid #eef2ff;
}
.form-section:last-of-type { margin-bottom: 0; }
.form-label {
    font-weight: 500;
    font-size: 13px;
    color: #475569;
    margin-bottom: 6px;
}
.form-control, .form-select {
    border-radius: 8px;
    border: 1.5px solid #e2e8f0;
    padding: 9px 14px;
    font-size: 14px;
    transition: all 0.2s;
}
.form-control:focus, .form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.12);
}

/* Buttons */
.btn-primary-gradient {
    background: var(--gradient);
    border: none;
    color: #fff;
    padding: 10px 28px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    letter-spacing: 0.3px;
}
.btn-primary-gradient:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(99,102,241,0.35);
    color: #fff;
}
.btn-primary-gradient:active { transform: translateY(0); }
.btn-primary-gradient:disabled {
    opacity: 0.55;
    transform: none;
    box-shadow: none;
}

/* Loading overlay */
.loading-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(255,255,255,0.88);
    backdrop-filter: blur(4px);
    z-index: 11000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}
.loading-overlay.show { display: flex; }
.loading-spinner-wrap {
    width: 64px;
    height: 64px;
    position: relative;
}
.loading-spinner-wrap::before {
    content: "";
    position: absolute;
    inset: 0;
    border: 4px solid #e2e8f0;
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
}
.loading-spinner-wrap::after {
    content: "";
    position: absolute;
    inset: 8px;
    border: 4px solid transparent;
    border-bottom-color: var(--primary-light);
    border-radius: 50%;
    animation: spin 1.2s linear infinite reverse;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading-text {
    margin-top: 20px;
    color: var(--primary);
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

/* Result icons */
.result-icon {
    width: 88px;
    height: 88px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}
.result-icon i { font-size: 44px; color: #fff; }
.result-icon.success {
    background: linear-gradient(135deg, #10b981, #34d399);
    box-shadow: 0 8px 24px rgba(16,185,129,0.3);
}
.result-icon.warning {
    background: linear-gradient(135deg, #f59e0b, #fbbf24);
    box-shadow: 0 8px 24px rgba(245,158,11,0.3);
}

/* Footer */
.install-footer {
    text-align: center;
    margin-top: 20px;
    padding-bottom: 20px;
    color: #94a3b8;
    font-size: 13px;
}

/* Responsive */
@media (max-width: 576px) {
    .install-header { padding: 36px 16px 32px; }
    .install-header h1 { font-size: 24px; }
    .step-content { padding: 24px 18px; }
    .stepper { padding: 20px 12px 16px; }
    .stepper-label { font-size: 12px; }
    .form-section { padding: 18px 14px; }
}

/* SweetAlert2 customization */
.swal2-popup { border-radius: 16px !important; padding: 28px 24px !important; }
.swal2-title { font-size: 20px !important; font-weight: 700 !important; color: #1e293b !important; }
.swal2-html-container { font-size: 15px !important; color: #64748b !important; line-height: 1.7 !important; }
.swal2-styled.swal2-confirm {
    background: var(--gradient) !important;
    border-radius: 8px !important;
    font-weight: 600 !important;
    padding: 10px 24px !important;
    box-shadow: 0 4px 12px rgba(99,102,241,0.3) !important;
}
.swal2-styled.swal2-cancel {
    border-radius: 8px !important;
    font-weight: 600 !important;
    padding: 10px 24px !important;
}
.swal2-styled.swal2-deny {
    border-radius: 8px !important;
    font-weight: 600 !important;
    padding: 10px 24px !important;
}