* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Poppins', Arial, sans-serif;
}

body {
    background: linear-gradient(135deg, #f0f4f8 0%, #e2e8f0 100%);
    min-height: 100vh;
    padding: 30px 20px;
}

.app-container {
    max-width: 1300px;
    margin: 0 auto;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ========== 头部设计 ========== */
.header {
    background: linear-gradient(135deg, #003d6b 0%, #002a4a 100%);
    color: white;
    padding: 22px 32px;
    border-radius: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    box-shadow: 0 10px 25px rgba(0,61,107,0.2);
}

.logo h1 {
    font-size: 26px;
    letter-spacing: -0.5px;
    margin-bottom: 5px;
}

.logo h1::before {
    content: "🎓 ";
    font-size: 28px;
}

.logo p {
    font-size: 13px;
    opacity: 0.85;
}

.user-info {
    background: rgba(255,255,255,0.12);
    padding: 8px 18px;
    border-radius: 50px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.user-info button {
    background: #e74c3c;
    padding: 6px 14px;
    border-radius: 30px;
    border: none;
    color: white;
    cursor: pointer;
    font-size: 13px;
    transition: 0.2s;
}

.user-info button:hover {
    background: #c0392b;
    transform: scale(1.02);
}

/* ========== 面板卡片 ========== */
.panel {
    background: white;
    border-radius: 24px;
    padding: 28px 30px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.05);
    display: none;
    margin-bottom: 20px;
    border: 1px solid rgba(0,61,107,0.08);
}

.panel.active-panel {
    display: block;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ========== 首页按钮 ========== */
.home-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin: 50px 0 30px;
    flex-wrap: wrap;
}

.home-buttons button {
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    background: linear-gradient(135deg, #003d6b 0%, #005a9c 100%);
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: 0.25s;
    box-shadow: 0 4px 10px rgba(0,61,107,0.25);
}

.home-buttons button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0,61,107,0.3);
}

/* ========== 表单样式 ========== */
.panel h3, .panel h4 {
    margin-bottom: 22px;
    color: #003d6b;
    font-weight: 600;
    border-left: 5px solid #e8a735;
    padding-left: 15px;
}

.form-card {
    background: #f9fbfd;
    padding: 22px 25px;
    border-radius: 20px;
    margin-bottom: 28px;
    border: 1px solid #eef2f6;
}

.panel input,
.panel select,
.panel textarea {
    width: 100%;
    padding: 12px 16px;
    margin-bottom: 16px;
    border: 1px solid #dce4ec;
    border-radius: 14px;
    font-size: 14px;
    transition: 0.2s;
    background: white;
}

.panel input:focus,
.panel select:focus,
.panel textarea:focus {
    outline: none;
    border-color: #003d6b;
    box-shadow: 0 0 0 3px rgba(0,61,107,0.1);
}

/* ========== 按钮配色 ========== */
#loginSubmitBtn,
#regSubmitBtn,
#searchBtn,
#adminSearchBtn,
#submitItemBtn {
    background: #003d6b;
    color: white;
    border: none;
    padding: 10px 22px;
    border-radius: 40px;
    cursor: pointer;
    font-weight: 500;
    transition: 0.2s;
}

#loginSubmitBtn:hover,
#regSubmitBtn:hover,
#searchBtn:hover,
#adminSearchBtn:hover,
#submitItemBtn:hover {
    background: #002a4a;
    transform: translateY(-1px);
}

#submitItemBtn {
    background: #27ae60;
}

#submitItemBtn:hover {
    background: #219a52;
}

#loginBackBtn,
#regBackBtn,
#logoutStudentBtn,
#logoutAdminBtn,
#globalLogoutBtn {
    background: #e74c3c;
    color: white;
    border: none;
    padding: 10px 22px;
    border-radius: 40px;
    cursor: pointer;
}

#resetSearchBtn,
#adminResetBtn {
    background: #95a5a6;
    color: white;
}

/* ========== 搜索栏 ========== */
.search-bar {
    display: flex;
    gap: 12px;
    margin-bottom: 25px;
    align-items: center;
    flex-wrap: wrap;
}

.search-bar input {
    flex: 2;
    margin-bottom: 0;
}

/* ========== 表格设计 ========== */
table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 18px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

table th {
    background: #003d6b;
    color: white;
    padding: 14px 12px;
    font-weight: 600;
    font-size: 13px;
}

table td {
    padding: 12px;
    border-bottom: 1px solid #edf2f7;
    font-size: 13px;
}

table tr:hover {
    background: #f8fafc;
}

/* ========== 图片缩略图 ========== */
img {
    border-radius: 10px;
    object-fit: cover;
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .app-container {
        padding: 0 15px;
    }

    .header {
        flex-direction: column;
        text-align: center;
        gap: 12px;
    }

    .home-buttons {
        flex-direction: column;
        align-items: center;
    }

    .home-buttons button {
        width: 80%;
    }

    .panel {
        padding: 20px;
    }

    table th, table td {
        padding: 8px 6px;
        font-size: 11px;
    }

    .search-bar {
        flex-direction: column;
    }

    .search-bar input {
        width: 100%;
    }
}
.status-pending { color: #e67e22; font-weight: bold; }
.status-resolved { color: #27ae60; font-weight: bold; }

.action-btn {
    padding: 5px 10px;
    margin: 2px;
    font-size: 11px;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    color: white;
}
.btn-edit { background: #3498db; }
.btn-edit:hover { background: #2980b9; }
.btn-resolve { background: #2ecc71; }
.btn-resolve:hover { background: #27ae60; }
.btn-delete { background: #e74c3c; }
.btn-delete:hover { background: #c0392b; }